Add some transforms of the kind X-Y>X -> 0>Y which are valid when there is no

overflow.  These subsume some existing equality transforms, so zap those.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125843 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/InstCombine/sub.ll

@@ -209,7 +209,7 @@ define i1 @test22(i32 %a, i32 %b) zeroext nounwind  {
 	%tmp5 = icmp eq i32 %tmp2, %tmp4	
 	ret i1 %tmp5
 ; CHECK: @test22
-; CHECK: %tmp5 = icmp eq i32 %a, %b
+; CHECK: %tmp5 = icmp eq i32 %b, %a
 ; CHECK: ret i1 %tmp5
 }