[llvm-objdump] Properly print MachO aarch64 addend relocations

[mstorsjo]

Summary

Previously such relocations fell into the last case for local symbols, using the relocation addend as symbol index, leading to a crash.

[t.p.northover]

llvm-commits doesn't appear to be involved here.

[mstorsjo]

In D35239#805124, @t.p.northover wrote:

llvm-commits doesn't appear to be involved here.

It does seem to be one of the issue subscribers to me, are there list delivery delays again?

[t.p.northover]

Looks reasonable to me.

llvm/trunk/test/tools/llvm-objdump/AArch64/macho-reloc-addend.test

+RUN: llvm-objdump -r %p/Inputs/reloc-addend.obj.macho-aarch64 | FileCheck %s
+
+CHECK-DAG: 0000000000000004 ARM64_RELOC_ADDEND 0x999
+CHECK-DAG: 0000000000000004 ARM64_RELOC_PAGEOFF12 _stringbuf
+CHECK-DAG: 0000000000000000 ARM64_RELOC_ADDEND 0x999
+CHECK-DAG: 0000000000000000 ARM64_RELOC_PAGE21 _stringbuf

llvm/trunk/tools/llvm-objdump/llvm-objdump.cpp

if (IsScattered) {
     fmt << format("0x%x", Val);
     return;
   }
 
   StringRef S;
   bool isExtern = O->getPlainRelocationExternal(RE);
   uint64_t Val = O->getPlainRelocationSymbolNum(RE);
 
-  if (isExtern) {
+  if (O->getAnyRelocationType(RE) == MachO::ARM64_RELOC_ADDEND) {
+    fmt << format("0x%x", Val);
+    return;
+  } else if (isExtern) {
     symbol_iterator SI = O->symbol_begin();
     advance(SI, Val);
     Expected<StringRef> SOrErr = SI->getName();
     if (!SOrErr)
       report_error(O->getFileName(), SOrErr.takeError());
     S = *SOrErr;
   } else {
     section_iterator SI = O->section_begin();