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

[Maksim Panchenko via llvm-commits]

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@@ -340,6 +354,113 @@ typedef std::unordered_map<BinaryFunction *, std::vector<BinaryFunction *>,
 
 namespace llvm {
 namespace bolt {
+/// Scans symbol table and creates a bit vector of memory addresses of vtables.
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maksfb wrote:

Refactor the code that handles vtable addresses. E.g. add a function `isInVTable(uint64_t)`. You can make the bit vector a member of the ICF pass class.

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