[Clang][MemProf] Add end-to-end test for PGHO rewriting (#169243)

Add an end-to-end (non-LTO) test verifying that the optimization
pipeline is set up correctly for Profile Guided Heap Optimization (PGHO)
transforms. Ensure that both PGHO and AllocToken can stack, and the
AllocToken pass does not interfere with PGHO and vice versa.

clang/test/CodeGen/memprof-pgho.cpp

@@ -0,0 +1,61 @@
+// Test end-to-end optimization pipeline with PGHO, that it does not interfere
+// with other allocation instrumentation features.
+//
+// RUN: split-file %s %t
+// RUN: llvm-profdata merge %t/memprof.yaml -o %t/use.profdata
+// RUN: %clang_cc1 -O2 -debug-info-kind=limited -fmemory-profile-use=%t/use.profdata -mllvm -optimize-hot-cold-new \
+// RUN:            %t/src.cpp -triple x86_64-linux-gnu -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,DEFAULT
+// RUN: %clang_cc1 -O2 -fsanitize=alloc-token -debug-info-kind=limited -fmemory-profile-use=%t/use.profdata -mllvm -optimize-hot-cold-new \
+// RUN:             %t/src.cpp -triple x86_64-linux-gnu -emit-llvm -o - | FileCheck %s --check-prefixes=CHECK,ALLOCTOKEN
+
+//--- memprof.yaml
+---
+HeapProfileRecords:
+  - GUID: 0x7f8d88fcc70a347b
+    AllocSites:
+    - Callstack:
+      - { Function: 0x7f8d88fcc70a347b, LineOffset: 1, Column: 10, IsInlineFrame: false }
+      - { Function: 0xdb956436e78dd5fa, LineOffset: 1, Column: 13, IsInlineFrame: false }
+      MemInfoBlock:
+        AllocCount: 1
+        TotalAccessCount: 0
+        MinAccessCount: 0
+        MaxAccessCount: 0
+        TotalSize: 10
+        MinSize: 10
+        MaxSize: 10
+        AllocTimestamp: 100
+        DeallocTimestamp: 100
+        TotalLifetime: 100000
+        MinLifetime: 100000
+        MaxLifetime: 100000
+        AllocCpuId: 0
+        DeallocCpuId: 0
+        NumMigratedCpu: 0
+        NumLifetimeOverlaps: 0
+        NumSameAllocCpu: 0
+        NumSameDeallocCpu: 0
+        DataTypeId: 0
+        TotalAccessDensity: 0
+        MinAccessDensity: 0
+        MaxAccessDensity: 0
+        TotalLifetimeAccessDensity: 0
+        MinLifetimeAccessDensity: 0
+        MaxLifetimeAccessDensity: 0
+        AccessHistogramSize: 0
+        AccessHistogram: 0
+...
+
+//--- src.cpp
+// CHECK-LABEL: define{{.*}} ptr @_Z3foov()
+// DEFAULT:    call {{.*}} ptr @_Znam12__hot_cold_t(i64 10, i8 -128)
+// ALLOCTOKEN: call {{.*}} ptr @__alloc_token__Znam12__hot_cold_t(i64 10, i8 -128, i64 1538840549748785101){{.*}} !alloc_token
+char *foo() {
+  return new char[10];
+}
+
+int main() {
+  char *a = foo();
+  delete[] a;
+  return 0;
+}