[clang] [clang] Differentiate between identifier and string EnumArgument (PR #68550)

[Sergei Barannikov via cfe-commits]

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@@ -45,7 +45,7 @@ int __attribute__((pcs("aapcs", "aapcs"))) pcs1(void); // expected-error {{'pcs'
 int __attribute__((pcs())) pcs2(void); // expected-error {{'pcs' attribute takes one argument}}
 int __attribute__((pcs(pcs1))) pcs3(void); // expected-error {{'pcs' attribute requires a string}} \
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s-barannikov wrote:

Here is an example when a string argument is not parsed as unevaluated string literal.

https://github.com/llvm/llvm-project/pull/68550