Add an integration test for comments before text blocks

PiperOrigin-RevId: 694499404

Author: cushon

core/src/test/resources/com/google/googlejavaformat/java/testdata/B377585941.input

@@ -0,0 +1,8 @@
+class T {
+  {
+    f(
+        /* foo */ """
+        hello
+        """);
+  }
+}

core/src/test/resources/com/google/googlejavaformat/java/testdata/B377585941.output

@@ -0,0 +1,8 @@
+class T {
+  {
+    f(
+        /* foo */ """
+                  hello
+                  """);
+  }
+}