[llvm] [BOLT] Add support for safe-icf (PR #116275)

[Amir Ayupov via llvm-commits]

================
@@ -0,0 +1,155 @@
+## Check that BOLT handles correctly folding functions with --icf=safe
+## that can be referenced through a non control flow instruction when ICP optimization is enabled.
+## This tests also checks that destructors are not folded.
+
+# REQUIRES: system-linux
+# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-linux %s -o %t1.o
+# RUN: %clang %cflags %t1.o -o %t.exe -Wl,-q
+# RUN: llvm-bolt --no-threads %t.exe --icf      -debug -debug-only=bolt-icf -o %t.bolt 2>&1 | FileCheck --check-prefix=ICFCHECK %s
+# RUN: llvm-bolt --no-threads %t.exe --icf=safe -debug -debug-only=bolt-icf -o %t.bolt 2>&1 | FileCheck --check-prefix=SAFEICFCHECK %s
+
+# ICFCHECK:      ICF iteration 1
+# ICFCHECK-NEXT: folding _ZN8Derived3D0Ev into _ZN8Derived2D0Ev
+# ICFCHECK-NEXT: folding _ZNK8Derived34funcEii into _ZNK8Derived24funcEii
+
+# SAFEICFCHECK: skipping function _ZNK8Derived34funcEii
+# SAFEICFCHECK-NEXT: ICF iteration 1
+# SAFEICFCHECK-NEXT: folding _ZN8Derived3D0Ev into _ZN8Derived2D0Ev
+# SAFEICFCHECK-NEXT: ===---------
+
+
+## generate profile
+## clang++ -O2 -fprofile-generate=. main.cpp   -c -o mainProf.o
+## PROF=test.profdata
+## clang++ -m64  -fprofile-use=$PROF \
+##   -mllvm -disable-icp=true -mllvm -print-after-all \
+##   -g0 -flto=thin -fwhole-program-vtables -fno-split-lto-unit -O2 \
+##   -fdebug-types-section \
+##   main.cpp -c -o mainProfLTO.bc
+## PASS='pgo-icall-prom'
+## clang++ -m64  -fprofile-use=$PROF \
+##   -O3 -Rpass=$PASS \
+##   -mllvm -print-before=$PASS \
+##   -mllvm -print-after=$PASS \
+##   -mllvm -filter-print-funcs=main \
+##   -mllvm -debug-only=$PASS \
+##   -x ir \
+##   mainProfLTO.bc -c -o mainProfFinal.o
+
+## class Base {
+## public:
+##   virtual int func(int a, int b) const = 0;
+##
+##   virtual ~Base() {};
+## };
+##
+## //namespace {
----------------
aaupov wrote:

```suggestion
```
here and below

https://github.com/llvm/llvm-project/pull/116275