tsan: switch from SSE3 to SSE4.2

Switch x86_64 requirement for optimized code from SSE3 to SSE4.2.
The new tsan runtime will need few instructions that are only
supported by SSE4:

_mm_max_epu32
_mm_extract_epi8
_mm_insert_epi32

SSE3 was introcued in 2004 and SSE4 in 2006:
https://en.wikipedia.org/wiki/SSE3
https://en.wikipedia.org/wiki/SSE4

We are still providing non-optimized C++ version of the code,
so either way it's possible to build tsan runtime for any CPU.

But for Go this will bump strict requirement for -race because
Go contains prebuilt versions and these will be built with -msse4.2.
But requiring a CPU produced at least in 2006 looks reasonable for
a debugging tool (more reasonable than disabling optimizations
for everybody).

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D106948