Remove an InstCombine that seems to have become redundant.

Assert that this doesn't fire - I'll remove all of this later, but just
leaving it in for a while in case this is firing & we just don't have
test coverage.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233116 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/InstCombine/2007-05-14-Crash.ll

@@ -15,4 +15,10 @@ entry:
         ret i8* %tmp35
 }
 
-
+define i32* @bar(%struct.abc* %abc) {
+entry:
+        %tmp1 = bitcast %struct.abc* %abc to %struct.def*
+        %tmp3 = getelementptr %struct.def, %struct.def* %tmp1, i32 0, i32 1
+        %tmp35 = bitcast %struct.abc* %tmp3 to i32*
+        ret i32* %tmp35
+}