b72a364bb5
unevaluated context Closes https://github.com/llvm/llvm-project/issues/58133 The direct cause for this issue is that the compilation process continues after it found it is in a invalid state. [expr.await]p2 says clearly that the co_await expressions are not allowed to appear in unevaluated context. So we can exit early in this case. It also reduces many redundant diagnostic messages (Such as 'expression with side effects has no effect in an unevaluated context').