[clang] [WebAssembly] Enable musttail only when tail-call is enabled (PR #163618)

[Jasmine Tang via cfe-commits]

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@@ -374,6 +374,8 @@ def err_ppc_impossible_musttail: Error<
   >;
 def err_aix_musttail_unsupported: Error<
   "'musttail' attribute is not supported on AIX">;
+def err_wasm_musttail_unsupported: Error<
+  "'musttail' attribute is not supported on this target without tail-call feature">;
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badumbatish wrote:

i see

https://github.com/llvm/llvm-project/pull/163618