cmd/link: remove R_ADDR relocation workaround for macho arm64

The workarounds doesn't seem necessary anymore, and blocks DWARF
on darwin/arm64.

Updates #24883.

Change-Id: Ic917c767d3b4f6c51be25566956296f5dd4ead10
Reviewed-on: https://go-review.googlesource.com/108655
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

src/cmd/link/internal/arm64/asm.go

@@ -150,10 +150,7 @@ func machoreloc1(arch *sys.Arch, out *ld.OutBuf, s *sym.Symbol, r *sym.Reloc, se
 
 	rs := r.Xsym
 
-	// ld64 has a bug handling MACHO_ARM64_RELOC_UNSIGNED with !extern relocation.
-	// see cmd/internal/ld/data.go for details. The workaround is that don't use !extern
-	// UNSIGNED relocation at all.
-	if rs.Type == sym.SHOSTOBJ || r.Type == objabi.R_CALLARM64 || r.Type == objabi.R_ADDRARM64 || r.Type == objabi.R_ADDR {
+	if rs.Type == sym.SHOSTOBJ || r.Type == objabi.R_CALLARM64 || r.Type == objabi.R_ADDRARM64 {
 		if rs.Dynid < 0 {
 			ld.Errorf(s, "reloc %d (%s) to non-macho symbol %s type=%d (%s)", r.Type, sym.RelocName(arch, r.Type), rs.Name, rs.Type, rs.Type)
 			return false

src/cmd/link/internal/ld/data.go

@@ -285,18 +285,8 @@ func relocsym(ctxt *Link, s *sym.Symbol) {
 						o = 0
 					}
 				} else if ctxt.HeadType == objabi.Hdarwin {
-					// ld64 for arm64 has a bug where if the address pointed to by o exists in the
-					// symbol table (dynid >= 0), or is inside a symbol that exists in the symbol
-					// table, then it will add o twice into the relocated value.
-					// The workaround is that on arm64 don't ever add symaddr to o and always use
-					// extern relocation by requiring rs->dynid >= 0.
 					if rs.Type != sym.SHOSTOBJ {
-						if ctxt.Arch.Family == sys.ARM64 && rs.Dynid < 0 {
-							Errorf(s, "R_ADDR reloc to %s+%d is not supported on darwin/arm64", rs.Name, o)
-						}
-						if ctxt.Arch.Family != sys.ARM64 {
-							o += Symaddr(rs)
-						}
+						o += Symaddr(rs)
 					}
 				} else if ctxt.HeadType == objabi.Hwindows {
 					// nothing to do