Eliminate the use of the global variable hack in the X86 target that was used

Eliminate the use of the global variable hack in the X86 target that was used
to get Visual Studio to link in X86.lib to the executables that need it.  There
is another way of doing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19252 91177308-0d34-0410-b5e6-96231b3b80d8