ExprMutAnalyzer considers all NoOp-casts for Arguments as 'adding const' and not treating them as mutation

[JonasToth]

Bugzilla Link	51756
Version	unspecified
OS	All

Extended Description

During testing of https://reviews.llvm.org/D54943 a new false positive in the 'ExprMutAnalyzer' was spotted.

Reproducer: https://godbolt.org/z/8EvsM3Eqe

Variables that are passed as arguments to a function are not considered to be mutated, if there is an implicit cast, that is 'NoOp' (in the assumption that this is a cast to 'const ').
Applying the '__unaligned' attribute introduces such a cast.
This results in the false analysis that this variable is not modified, where in fact it is.

'ExprMutAnalyzer.cpp, Line 295'

[JonasToth]

assigned to @JonasToth