Revert "Take account of boolean vector contents when promoting a build vector...

Revert "Take account of boolean vector contents when promoting a build vector from i1 to some other type.  rdar://problem/12210060"

This reverts commit 5dd9e214fb92847e947f9edab170f9b4e52b908f.

Thanks to Duncan for explaining how this should have been done.

Conflicts:

	test/CodeGen/X86/vec_select.ll

llvm-svn: 163064