[compiler-rt] [tsan] Unify aarch64 mapping

This patch unify the 39 and 42-bit support for AArch64 by using an external
memory read to check the runtime detected VMA and select the better mapping
and transformation.  Although slower, this leads to same instrumented binary
to be independent of the kernel.

Along with this change this patch also fix some 42-bit failures with
ALSR disable by increasing the upper high app memory threshold and also
the 42-bit madvise value for non large page set.

llvm-svn: 254151