[llvm] [BOLT] Support computed goto and allow map addrs inside functions (PR #120267)

[Maksim Panchenko via llvm-commits]

================
@@ -2439,6 +2439,33 @@ void RewriteInstance::readDynamicRelocations(const SectionRef &Section,
     if (Symbol)
       SymbolIndex[Symbol] = getRelocationSymbol(InputFile, Rel);
 
+    const uint64_t ReferencedAddress = SymbolAddress + Addend;
+    BinaryFunction *Func =
+        BC->getBinaryFunctionContainingAddress(ReferencedAddress);
+
+    if (Relocation::isRelative(RType) && SymbolAddress == 0) {
+      if (Func) {
+        if (!Func->isInConstantIsland(ReferencedAddress)) {
+          if (const uint64_t ReferenceOffset =
+                  ReferencedAddress - Func->getAddress()) {
+            Func->addEntryPointAtOffset(ReferenceOffset);
+          } else if (ReferencedAddress < Func->getAddress()) {
+            BC->errs() << "BOLT-ERROR: Unable to compute symbol offset.\n";
+            exit(1);
+          }
+        } else {
+          BC->errs() << "BOLT-ERROR: referenced address: " << ReferencedAddress
+                     << " is in constant island of function : " << *Func
+                     << "\n";
+          exit(1);
+        }
+      }
+    } else if (Relocation::isRelative(RType) && SymbolAddress != 0) {
+      BC->errs() << "BOLT-ERROR: symbol address non zero for RELATIVE "
+                    "relocation type.\n";
----------------
maksfb wrote:

nit:
```suggestion
                    "relocation type\n";
```

https://github.com/llvm/llvm-project/pull/120267