[arm64] Assembler support for internal references.

src/arm64/assembler-arm64-inl.h

Index: src/arm64/assembler-arm64-inl.h
diff --git a/src/arm64/assembler-arm64-inl.h b/src/arm64/assembler-arm64-inl.h
index 2d2b7e6dd3344eb3eb8a814ec094ca1cd2a4af10..e27ad4fe0cf39bc849b529d8823ca2d5b18eedef 100644
--- a/src/arm64/assembler-arm64-inl.h
+++ b/src/arm64/assembler-arm64-inl.h
@@ -18,7 +18,12 @@ bool CpuFeatures::SupportsCrankshaft() { return true; }
 
 
 void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
-  UNIMPLEMENTED();
+  // On arm64 only internal references need extra work.
+  DCHECK(RelocInfo::IsInternalReference(rmode_));
+
+  // Absolute code pointer inside code object moves with the code object.
+  intptr_t* p = reinterpret_cast<intptr_t*>(pc_);
+  *p += delta;  // Relocate entry.
 }