[VPlan] Use opaque pointers in VPlan unit test IR (llvm#69947)

Updates the unit tests for VPlan to use opaque pointers in strings
containing LLVM IR. This is to match the similar adjustments being made
for lit tests to use opaque pointers.

Author: calebwat

llvm/unittests/Transforms/Vectorize/VPlanHCFGTest.cpp

@@ -21,15 +21,15 @@ class VPlanHCFGTest : public VPlanTestBase {};
 
 TEST_F(VPlanHCFGTest, testBuildHCFGInnerLoop) {
   const char *ModuleString =
-      "define void @f(i32* %A, i64 %N) {\n"
+      "define void @f(ptr %A, i64 %N) {\n"
       "entry:\n"
       "  br label %for.body\n"
       "for.body:\n"
       "  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]\n"
-      "  %arr.idx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv\n"
-      "  %l1 = load i32, i32* %arr.idx, align 4\n"
+      "  %arr.idx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv\n"
+      "  %l1 = load i32, ptr %arr.idx, align 4\n"
       "  %res = add i32 %l1, 10\n"
-      "  store i32 %res, i32* %arr.idx, align 4\n"
+      "  store i32 %res, ptr %arr.idx, align 4\n"
       "  %indvars.iv.next = add i64 %indvars.iv, 1\n"
       "  %exitcond = icmp ne i64 %indvars.iv.next, %N\n"
       "  br i1 %exitcond, label %for.body, label %for.end\n"
@@ -148,15 +148,15 @@ compound=true
 
 TEST_F(VPlanHCFGTest, testVPInstructionToVPRecipesInner) {
   const char *ModuleString =
-      "define void @f(i32* %A, i64 %N) {\n"
+      "define void @f(ptr %A, i64 %N) {\n"
       "entry:\n"
       "  br label %for.body\n"
       "for.body:\n"
       "  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]\n"
-      "  %arr.idx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv\n"
-      "  %l1 = load i32, i32* %arr.idx, align 4\n"
+      "  %arr.idx = getelementptr inbounds i32, ptr %A, i64 %indvars.iv\n"
+      "  %l1 = load i32, ptr %arr.idx, align 4\n"
       "  %res = add i32 %l1, 10\n"
-      "  store i32 %res, i32* %arr.idx, align 4\n"
+      "  store i32 %res, ptr %arr.idx, align 4\n"
       "  %indvars.iv.next = add i64 %indvars.iv, 1\n"
       "  %exitcond = icmp ne i64 %indvars.iv.next, %N\n"
       "  br i1 %exitcond, label %for.body, label %for.end\n"