[compiler-rt] Fix memory allocator for dynamic address space

[compiler-rt] Fix memory allocator for dynamic address space

Summary:
The sanitizer allocators can works with a dynamic address space
(i.e. specified with ~0ULL).

Unfortunately, the code was broken on GetMetadata and GetChunkIdx.

The current patch is moving the Win64 memory test to a dynamic
address space. There is a migration to move every concept to a
dynamic address space on windows.

To have a better coverage, the unittest are now testing
dynamic address space on other platforms too.

Reviewers: rnk, kcc

Subscribers: kubabrecka, dberris, llvm-commits, chrisha

Differential Revision: https://reviews.llvm.org/D23170

llvm-svn: 277745