[TSan] Build TSan runtime with -fPIE.
This removes all register spills from the performance-critical __tsan_{read,write}{1,2,4,8} functions when the host compiler is GCC.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@178340 91177308-0d34-0410-b5e6-96231b3b80d8
[tsan] restore performance critical inlining in tsan: remove static from ALWAYS_INLINE, use ALWAYS_INLINE USED for critical functions. 

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@178341 91177308-0d34-0410-b5e6-96231b3b80d8