remove this xfail'd test, move it to the X86 readme.

llvm-svn: 36800

llvm/test/CodeGen/X86/overlap-add.ll

@@ -1,28 +0,0 @@
-;; X's live range extends beyond the shift, so the register allocator
-;; cannot coalesce it with Y.  Because of this, a copy needs to be
-;; emitted before the shift to save the register value before it is
-;; clobbered.  However, this copy is not needed if the register
-;; allocator turns the shift into an LEA.  This also occurs for ADD.
-
-; Check that the shift gets turned into an LEA.
-
-; RUN: llvm-upgrade < %s | llvm-as | llc -march=x86 -x86-asm-syntax=intel | \
-; RUN:   not grep {mov E.X, E.X}
-
-; FIXME: We need live variable information about flags to do this xform safely. :(
-; XFAIL: *
-
-%G = external global int
-
-int %test1(int %X, int %Y) {
-	%Z = add int %X, %Y
-	volatile store int %Y, int* %G
-	volatile store int %Z, int* %G
-	ret int %X
-}
-
-int %test2(int %X) {
-	%Z = add int %X, 1  ;; inc
-	volatile store int %Z, int* %G
-	ret int %X
-}