Remove br i1 undef in InstSimplify directory

Author: leewei05

llvm/test/Transforms/InstSimplify/dead-code-removal.ll

@@ -1,15 +1,15 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -passes=instsimplify -S < %s | FileCheck %s
 
-define void @foo() nounwind {
+define void @foo(i1 %arg) nounwind {
 ; CHECK-LABEL: @foo(
-; CHECK-NEXT:    br i1 undef, label [[TMP1:%.*]], label [[TMP2:%.*]]
+; CHECK-NEXT:    br i1 %arg, label [[TMP1:%.*]], label [[TMP2:%.*]]
 ; CHECK:       1:
 ; CHECK-NEXT:    br label [[TMP1]]
 ; CHECK:       2:
 ; CHECK-NEXT:    ret void
 ;
-  br i1 undef, label %1, label %4
+  br i1 %arg, label %1, label %4
 
 ; <label>:1                                       ; preds = %1, %0
   %2 = phi i32 [ %3, %1 ], [ undef, %0 ]

llvm/test/Transforms/InstSimplify/require-dominator.ll

@@ -7,8 +7,8 @@
 target triple = "x86_64-grtev4-linux-gnu"
 
 ; Function Attrs: nounwind uwtable
-define void @foo(ptr) #1 align 2 {
-  br i1 undef, label %exit, label %2
+define void @foo(ptr, i1 %arg) #1 align 2 {
+  br i1 %arg, label %exit, label %2
 
 ; <label>:2:
   %3 = tail call ptr @_Znwm(i64 56) #10