[clang] [CLANG] Full support of complex multiplication and division. (PR #81514)

[Zahira Ammarguellat via cfe-commits]

zahiraam wrote:

@andykaylor  I am opening up this for review in order to have other people chime in. 

@AaronBallman what do you think about the warnings (and the rest of course)? 
-fcomplex-arithmetic=full -ffast-math generates this warning: "use of nnan or ninf flags in the presence of '-fcomplex-arithmetic=full' option".
-ffast-math -fcomplex-arithmetic=full generates this warning: "overriding '-fcomplex-arithmetic=basic' option with '-fcomplex-arithmetic=full'
-ffast-math sets the range to "basic" and when "full" is met. the value of range is overridden, hence the warning. 
Is it OK that the warnings are not symmetrical? Should we generate the first warning also for the second case or is it too redundant?

@MaskRay what do you think about aliasing the old options to the new one? 

@rjmccall Would you mind taking a look at this?.

Thanks all!


https://github.com/llvm/llvm-project/pull/81514