[X86][MS-InlineAsm] Use exact conditions to recognize MS global variables

D115225 tried to roll back the effects on symbols of MS inline asm
introduced by D113096. But the combination of the conditions cannot
match all the changes. As a result, there are still fails after the
patch.

This patch fixes the problem by checking the exact conditions for MS
global variables, i.e., variable (by FrontendSize != 0) + non rip/eip
(by DefaultBaseReg == 0), so that we can fully roll back for D113096.

Reviewed By: skan

Differential Revision: https://reviews.llvm.org/D116090