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

[Hubert Tong via cfe-commits]

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@@ -9401,7 +9318,9 @@ def _SLASH_source_charset : CLCompileJoined<"source-charset:">,
   HelpText<"Set source encoding, supports only UTF-8">,
   Alias<finput_charset_EQ>;
 def _SLASH_execution_charset : CLCompileJoined<"execution-charset:">,
-  HelpText<"Set runtime encoding, supports only UTF-8">,
+  HelpText<"Set the execution <charset> for string and character literals. "
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hubert-reinterpretcast wrote:

Okay. It seems like C landed on having coded character sets and encodings of them. The option does specify the encoding, and the both standards use "literal" as the modifier applied to the term "encoding".

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