tsan: support pie binaries on newer kernels

4.1+ Linux kernels map pie binaries at 0x55:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d1fd836dcf00d2028c700c7e44d2c23404062c90
Currently tsan does not support app memory at 0x55 (https://github.com/google/sanitizers/issues/503).
Older kernels also map pie binaries at 0x55 when ASLR is disables (most notably under gdb).

This change extends tsan mapping for linux/x86_64 to cover 0x554-0x568 app range and fixes both 4.1+ kernels and gdb.

This required to slightly shrink low and high app ranges and move heap. The mapping become even more non-linear, since now we xor lower bits. Now even a continuous app range maps to split, intermixed shadow ranges. This breaks ShadowToMemImpl as it assumes linear mapping at least within a continuous app range (however it turned out to be already broken at least on arm64/42-bit vma as uncovered by r281970). So also change ShadowToMemImpl to hopefully a more robust implementation that does not assume a linear mapping.

llvm-svn: 282152