[compiler-rt] Reland '[hwasan] Add fixed_shadow_base flag (#73980)' (PR #95445)

[Florian Mayer via llvm-commits]

fmayer wrote:

> > Now also on the correct PR:
> > I think that's incorrect:
> > ```
> > #ifndef SANITIZER_CAN_USE_PREINIT_ARRAY
> > #if (SANITIZER_LINUX || SANITIZER_FUCHSIA || SANITIZER_NETBSD) && !defined(PIC)
> > #define SANITIZER_CAN_USE_PREINIT_ARRAY 1
> > // Before Solaris 11.4, .preinit_array is fully supported only with GNU ld.
> > // FIXME: Check for those conditions.
> > ```
> > 
> > 
> >     
> >       
> >     
> > 
> >       
> >     
> > 
> >     
> >   
> > ANDROID is Linux and does in fact _support_ preinit array, we just don't use it for HWASan.
> 
> I believe it's disabled because hwasan is dynamic lib. Either way this patch is correct for the current state of the code.

I'll double check but I don't think it is, the bug still happened on Android when I applied this

https://github.com/llvm/llvm-project/pull/95445