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

[Hubert Tong via llvm-commits]

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@@ -0,0 +1,46 @@
+// RUN: %clang %s -std=c++17 -emit-llvm -S -target s390x-ibm-zos -o - | FileCheck %s
+
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hubert-reinterpretcast wrote:

There should be tests for character literals in `#if`.

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