[BOLT][NFCI] Fix return type of BC::getSignedValueAtAddress (#91664)

Author: aaupov

bolt/include/bolt/Core/BinaryContext.h

@@ -1224,8 +1224,7 @@ class BinaryContext {
 
   /// Return a signed value of \p Size stored at \p Address. The address has
   /// to be a valid statically allocated address for the binary.
-  ErrorOr<uint64_t> getSignedValueAtAddress(uint64_t Address,
-                                            size_t Size) const;
+  ErrorOr<int64_t> getSignedValueAtAddress(uint64_t Address, size_t Size) const;
 
   /// Special case of getUnsignedValueAtAddress() that uses a pointer size.
   ErrorOr<uint64_t> getPointerAtAddress(uint64_t Address) const {

bolt/lib/Core/BinaryContext.cpp

@@ -2217,8 +2217,8 @@ ErrorOr<uint64_t> BinaryContext::getUnsignedValueAtAddress(uint64_t Address,
   return DE.getUnsigned(&ValueOffset, Size);
 }
 
-ErrorOr<uint64_t> BinaryContext::getSignedValueAtAddress(uint64_t Address,
-                                                         size_t Size) const {
+ErrorOr<int64_t> BinaryContext::getSignedValueAtAddress(uint64_t Address,
+                                                        size_t Size) const {
   const ErrorOr<const BinarySection &> Section = getSectionForAddress(Address);
   if (!Section)
     return std::make_error_code(std::errc::bad_address);

bolt/lib/Rewrite/LinuxKernelRewriter.cpp

@@ -393,7 +393,7 @@ void LinuxKernelRewriter::processLKKSymtab(bool IsGPL) {
 
   for (uint64_t I = 0; I < SectionSize; I += 4) {
     const uint64_t EntryAddress = SectionAddress + I;
-    ErrorOr<uint64_t> Offset = BC.getSignedValueAtAddress(EntryAddress, 4);
+    ErrorOr<int64_t> Offset = BC.getSignedValueAtAddress(EntryAddress, 4);
     assert(Offset && "Reading valid PC-relative offset for a ksymtab entry");
     const int32_t SignedOffset = *Offset;
     const uint64_t RefAddress = EntryAddress + SignedOffset;