Revert "Remove an InstCombine that seems to have become redundant."

Assertion fires in compiler-rt. Guess it does fire..

This reverts commit r233116.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@233121 91177308-0d34-0410-b5e6-96231b3b80d8

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

@@ -15,10 +15,4 @@ 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
-}
+