[clang] [clang]Avoid to check created local variable multiple time when evaluating (PR #69106)

[via cfe-commits]

mzyKi wrote:

I test example in branch llvmorg-16.0.6,ExprConstant.cpp also has this assertion but it will not result in crash.So I think should not  remove this assertion and try to find the reason ```!Result.isAbsent()```  Maybe somewhere change its valueKind.

https://github.com/llvm/llvm-project/pull/69106