[WinASan] Don't instrument globals in sections containing '$'

Such globals are very likely to be part of a sorted section array, such
the .CRT sections used for dynamic initialization. The uses its own
sorted sections called ATL$__a, ATL$__m, and ATL$__z. Instead of special
casing them, just look for the dollar sign, which is what invokes linker
section sorting for COFF.

Avoids issues with ASan and the ATL uncovered after we started
instrumenting comdat globals on COFF.

llvm-svn: 334653