[llvm] [SampleFDO] Match functions with the same base function name (PR #126688)

[Lei Wang via llvm-commits]

wlei-llvm wrote:

> > there may be no anchors for the profile or IR but the functions still match
> 
> When does that happen?

I observed some cases: 
The class uses template type(typename), and there could be changes for the type(like using bitset<size> and the size changes)
and all the functions in the class use this type as parameter, so when the type changed, all the function's signature changed.
In a caller function that uses the functions, those callsite anchors are all mismatched. This is a match case as just simple bitset size change.

https://github.com/llvm/llvm-project/pull/126688