Stop using prefix_tys

[dingxiangfei2009]

This is a member of a patch series to replace #135527.

This function hints at an early commitment to coroutine memory layout. We should not give promises on how upvars are allocated.

[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

[rustbot]

r? @tiif

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[cjgillot]

Do you mind rebasing and running x.py fmt to remove formatting changes? That will make review much easier.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[dingxiangfei2009]

@rustbot ready

[rust-log-analyzer]

The job aarch64-gnu-llvm-21-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

---- [debuginfo-gdb] tests/debuginfo/coroutine-objects.rs stdout ----
NOTE: compiletest thinks it is using GDB version 16003000

error: check directive(s) from `/checkout/tests/debuginfo/coroutine-objects.rs` not found in debugger output. errors:
    (coroutine-objects.rs:16) `$1 = coroutine_objects::main::{coroutine_env#0}::Unresumed{_ref__a: 0x[...]}`
    (coroutine-objects.rs:19) `$2 = coroutine_objects::main::{coroutine_env#0}::Suspend0{c: 6, d: 7, _ref__a: 0x[...]}`
    (coroutine-objects.rs:22) `$3 = coroutine_objects::main::{coroutine_env#0}::Suspend1{c: 7, d: 8, _ref__a: 0x[...]}`
    (coroutine-objects.rs:25) `$4 = coroutine_objects::main::{coroutine_env#0}::Returned{_ref__a: 0x[...]}`
status: exit status: 0
command: PYTHONPATH="/checkout/src/etc" "/usr/bin/gdb" "-quiet" "-batch" "-nx" "-command=/checkout/obj/build/aarch64-unknown-linux-gnu/test/debuginfo/coroutine-objects.gdb/coroutine-objects.debugger.script"
--- stdout -------------------------------
GNU gdb (Ubuntu 16.3-1ubuntu2) 16.3
Copyright (C) 2024 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "aarch64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word".
To enable execution of this file add
 add-auto-load-safe-path /checkout/src/etc/gdb_load_rust_pretty_printers.py
line to your configuration file "/home/user/.config/gdb/gdbinit".
To completely disable this security protection add
 set auto-load safe-path /
line to your configuration file "/home/user/.config/gdb/gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:
 info "(gdb)Auto-loading safe path"
Breakpoint 1 at 0x1114: file /checkout/tests/debuginfo/coroutine-objects.rs, line 79.
Breakpoint 2 at 0x1150: file /checkout/tests/debuginfo/coroutine-objects.rs, line 81.
Breakpoint 3 at 0x1170: file /checkout/tests/debuginfo/coroutine-objects.rs, line 83.
Breakpoint 4 at 0x1190: file /checkout/tests/debuginfo/coroutine-objects.rs, line 85.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".

Breakpoint 1, coroutine_objects::main () at /checkout/tests/debuginfo/coroutine-objects.rs:79
79     _zzz(); // #break
$1 = coroutine_objects::main::{coroutine_env#0}::Unresumed

Breakpoint 2, coroutine_objects::main () at /checkout/tests/debuginfo/coroutine-objects.rs:81
81     _zzz(); // #break
$2 = coroutine_objects::main::{coroutine_env#0}::Suspend0{c: 6, d: 7}

Breakpoint 3, coroutine_objects::main () at /checkout/tests/debuginfo/coroutine-objects.rs:83
83     _zzz(); // #break
$3 = coroutine_objects::main::{coroutine_env#0}::Suspend1{c: 7, d: 8}
6 7 8

Breakpoint 4, coroutine_objects::main () at /checkout/tests/debuginfo/coroutine-objects.rs:85
85     _zzz(); // #break
$4 = coroutine_objects::main::{coroutine_env#0}::Returned
A debugging session is active.

 Inferior 1 [process 244469] will be killed.

Quit anyway? (y or n) [answered Y; input not from terminal]
------------------------------------------
--- stderr -------------------------------
warning: File "/checkout/src/etc/gdb_load_rust_pretty_printers.py" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
------------------------------------------

---- [debuginfo-gdb] tests/debuginfo/coroutine-objects.rs stdout end ----
---- [debuginfo-gdb] tests/debuginfo/issue-57822.rs stdout ----
NOTE: compiletest thinks it is using GDB version 16003000

error: check directive(s) from `/checkout/tests/debuginfo/issue-57822.rs` not found in debugger output. errors:
    (issue-57822.rs:18) `$2 = issue_57822::main::{coroutine_env#3}::Unresumed{a: issue_57822::main::{coroutine_env#2}::Unresumed{y: 2}}`
the following subset of check directive(s) was found successfully:
    (issue-57822.rs:15) `$1 = issue_57822::main::{closure_env#1} {f: issue_57822::main::{closure_env#0} {x: 1}}`
status: exit status: 0
command: PYTHONPATH="/checkout/src/etc" "/usr/bin/gdb" "-quiet" "-batch" "-nx" "-command=/checkout/obj/build/aarch64-unknown-linux-gnu/test/debuginfo/issue-57822.gdb/issue-57822.debugger.script"
--- stdout -------------------------------
GNU gdb (Ubuntu 16.3-1ubuntu2) 16.3
Copyright (C) 2024 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "aarch64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word".
To enable execution of this file add
 add-auto-load-safe-path /checkout/src/etc/gdb_load_rust_pretty_printers.py
line to your configuration file "/home/user/.config/gdb/gdbinit".
To completely disable this security protection add
 set auto-load safe-path /
line to your configuration file "/home/user/.config/gdb/gdbinit".
For more information about this security protection see the
"Auto-loading safe path" section in the GDB manual.  E.g., run from the shell:
 info "(gdb)Auto-loading safe path"
Breakpoint 1 at 0xbd4: file /checkout/tests/debuginfo/issue-57822.rs, line 52.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/aarch64-linux-gnu/libthread_db.so.1".

Breakpoint 1, issue_57822::main () at /checkout/tests/debuginfo/issue-57822.rs:52
52     zzz(); // #break
$1 = issue_57822::main::{closure_env#1} {f: issue_57822::main::{closure_env#0} {x: 1}}
$2 = issue_57822::main::{coroutine_env#3}::Unresumed
A debugging session is active.

 Inferior 1 [process 245016] will be killed.

Quit anyway? (y or n) [answered Y; input not from terminal]
------------------------------------------
--- stderr -------------------------------
warning: File "/checkout/src/etc/gdb_load_rust_pretty_printers.py" auto-loading has been declined by your `auto-load safe-path' set to "$debugdir:$datadir/auto-load".
------------------------------------------

---- [debuginfo-gdb] tests/debuginfo/issue-57822.rs stdout end ----

failures: