Fix PR3701. 1. X86 target renamed eflags register to flags. This matches what llvm...

Fix PR3701. 1. X86 target renamed eflags register to flags. This matches what llvm-gcc generates so codegen knows flags register is being clobbered by inline asm. 2. BURR scheduler should also check if inline asm nodes can clobber "live" physical registers. Previously it was only checking target nodes with implicit defs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65996 91177308-0d34-0410-b5e6-96231b3b80d8