[BOLT] Refactor tracking internals of BinaryFunction. NFCI (#167074)

In addition to tracking offsets inside a `BinaryFunction` that are
referenced by data relocations, we need to track those relocations too.
Plus, we will need to map symbols referenced by such relocations back to
the containing function.

This change introduces `BinaryFunction::InternalRefDataRelocations` to
track the aforementioned relocations and expands
`BinaryContext::SymbolToFunctionMap` to include local/temp symbols
involved in relocation processing.

There is no functional change introduced that should affect the output.
Future PRs will use the new tracking capabilities.

1 files changed, 4 insertions, 2 deletions

diff --git a/bolt/lib/Rewrite/RewriteInstance.cpp b/bolt/lib/Rewrite/RewriteInstance.cpp
index ab3431ef8bd5..5769577aa3f7 100644
--- a/bolt/lib/Rewrite/RewriteInstance.cpp
+++ b/bolt/lib/Rewrite/RewriteInstance.cpp
@@ -2954,8 +2954,10 @@ void RewriteInstance::handleRelocation(const SectionRef &RelocatedSection,
           // if-condition above) so we're handling a relocation from a function
           // to itself. RISC-V uses such relocations for branches, for example.
           // These should not be registered as externally references offsets.
-          if (!ContainingBF)
-            ReferencedBF->registerReferencedOffset(RefFunctionOffset);
+          if (!ContainingBF && !ReferencedBF->isInConstantIsland(Address)) {
+            ReferencedBF->registerInternalRefDataRelocation(RefFunctionOffset,
+                                                            Rel.getOffset());
+          }
         }
         if (opts::Verbosity > 1 &&
             BinarySection(*BC, RelocatedSection).isWritable())