Revert "cmd/link: only embed runtime.goarm in the module that contains the runtime package"

This reverts commit bf99d8f8.

Change-Id: Id4374ed35802cfbfe11e015ccd9526d3497dc8cc
Reviewed-on: https://go-review.googlesource.com/14239Reviewed-by: Dave Cheney <dave@cheney.net>

src/cmd/link/internal/arm/obj.go

@@ -169,4 +169,10 @@ func archinit() {
 	if ld.INITDAT != 0 && ld.INITRND != 0 {
 		fmt.Printf("warning: -D0x%x is ignored because of -R0x%x\n", uint64(ld.INITDAT), uint32(ld.INITRND))
 	}
+
+	// embed goarm to runtime.goarm
+	s := ld.Linklookup(ld.Ctxt, "runtime.goarm", 0)
+
+	s.Type = obj.SRODATA
+	ld.Adduint8(ld.Ctxt, s, uint8(ld.Ctxt.Goarm))
 }

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

@@ -558,30 +558,19 @@ func loadlib() {
 	Ctxt.Tlsg = tlsg
 
 	moduledata := Linklookup(Ctxt, "runtime.firstmoduledata", 0)
-	if moduledata.Type != 0 && moduledata.Type != obj.SDYNIMPORT {
-		// If the module (toolchain-speak for "executable or shared
-		// library") we are linking contains the runtime package, it
-		// will define the runtime.firstmoduledata symbol and we
-		// truncate it back to 0 bytes so we can define its entire
-		// contents in symtab.go:symtab().
-		moduledata.Size = 0
-
-		// In addition, on ARM, the runtime depends on the linker
-		// recording the value of GOARM.
-		if Thearch.Thechar == '5' {
-			s := Linklookup(Ctxt, "runtime.goarm", 0)
-
-			s.Type = obj.SRODATA
-			Adduint8(Ctxt, s, uint8(Ctxt.Goarm))
-		}
-	} else {
-		// If OTOH the module does not contain the runtime package,
-		// create a local symbol for the moduledata.
+	if moduledata.Type == 0 || moduledata.Type == obj.SDYNIMPORT {
+		// If the module we are linking does not define the
+		// runtime.firstmoduledata symbol, create a local symbol for
+		// the moduledata.
 		moduledata = Linklookup(Ctxt, "local.moduledata", 0)
 		moduledata.Local = true
+	} else {
+		// If OTOH the module does define the symbol, we truncate the
+		// symbol back to 0 bytes so we can define its entire
+		// contents.
+		moduledata.Size = 0
 	}
-	// In all cases way we mark the moduledata as noptrdata to hide it from
-	// the GC.
+	// Either way we mark it as noptrdata to hide it from the GC.
 	moduledata.Type = obj.SNOPTRDATA
 	moduledata.Reachable = true
 	Ctxt.Moduledata = moduledata