add a testcase, which we already handle

llvm-svn: 17737

llvm/test/Regression/Transforms/InstCombine/phi.ll

@@ -33,7 +33,7 @@ Exit:
 	ret int %B
 }
 
-int %test3(bool %b) {
+int %test4(bool %b) {
 BB0:  ret int 7                                 ; Loop is unreachable
 
 Loop:
@@ -43,3 +43,13 @@ L2:
 	br label %Loop
 }
 
+int %test5(int %a, bool %b) {
+BB0: br label %Loop
+
+Loop:
+        %B = phi int [%A, %BB0], [undef, %Loop]    ; PHI has same value always.
+        br bool %b, label %Loop, label %Exit
+Exit:
+        ret int %B
+}
+