[clang] [Clang] Avoid assertion failure for initialized extern aliases (PR #223124)

[Aaron Ballman via cfe-commits]

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@@ -36,3 +36,6 @@ int a10() __attribute__((weakref ("foo")));
 static int v __attribute__((weakref(a1), alias("foo"))); // expected-error {{expected string literal as argument of 'weakref' attribute}}
 
 __attribute__((weakref ("foo"))) auto a11 = 1; // expected-error {{weakref declaration must have internal linkage}}
+// expected-error at -1 {{definition 'a11' cannot also be an alias}}
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AaronBallman wrote:

Separately is fine by me, I expect this to be a pretty rare failure mode.

https://github.com/llvm/llvm-project/pull/223124