[clang] [llvm] [Coroutines] Drop dead instructions more aggressively in addMustTailToCoroResumes() (PR #85271)

[via cfe-commits]

================
@@ -0,0 +1,65 @@
+// This tests that the symmetric transfer at the final suspend point could happen successfully.
----------------
zmodem wrote:

Done.

https://github.com/llvm/llvm-project/pull/85271