update definitions after hiframes pass

Author: Ehsan Totoni

hpat/hiframes.py

@@ -1,6 +1,6 @@
 from __future__ import print_function, division, absolute_import
 import types as pytypes  # avoid confusion with numba.types
-
+import collections
 import numba
 from numba import ir, config, ir_utils, types
 from numba import compiler as numba_compiler
@@ -78,6 +78,7 @@ def run(self):
         self.typemap, self.return_type, self.calltypes = numba_compiler.type_inference_stage(
                 self.typingctx, self.func_ir, self.args, None)
         self.fix_series_filter(self.func_ir.blocks)
+        self.func_ir._definitions = _get_definitions(self.func_ir.blocks)
         dprint_func_ir(self.func_ir, "after hiframes")
         if config.DEBUG_ARRAY_OPT==1:
             print("df_vars: ", self.df_vars)
@@ -535,3 +536,11 @@ def include_new_blocks(blocks, new_blocks, label, new_body):
     inner_blocks[inner_last_label].body.append(ir.Jump(label, loc))
     #new_body.clear()
     return label
+
+def _get_definitions(blocks):
+    definitions = collections.defaultdict(list)
+    for block in blocks.values():
+        for inst in block.body:
+            if isinstance(inst, ir.Assign):
+                definitions[inst.target.name].append(inst.value)
+    return definitions