[clang] [llvm] Enable fexec-charset option (PR #138895)

[Abhina Sree via cfe-commits]

================
@@ -0,0 +1,35 @@
+// RUN: %clang_cc1 %s -emit-llvm -triple s390x-none-zos -fexec-charset IBM-1047 -o - | FileCheck %s
----------------
abhina-sree wrote:

I have decided to keep wide strings/characters out of the scope of this PR but eventually it should be added when fwide-exec-charset is supported

https://github.com/llvm/llvm-project/pull/138895