runtime, cmd/link: fix netbsd/arm EABI support

Fixes reported by oshimaya (see #13806).

Fixes #13806.

Change-Id: I9b659ab918a34bc5f7c58f3d7f59058115b7f776
Reviewed-on: https://go-review.googlesource.com/31651Reviewed-by: Minux Ma <minux@golang.org>

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

@@ -945,11 +945,10 @@ func Elfinit(ctxt *Link) {
 		ehdr.phentsize = ELF64PHDRSIZE /* Must be ELF64PHDRSIZE */
 		ehdr.shentsize = ELF64SHDRSIZE /* Must be ELF64SHDRSIZE */
 
-	// we use EABI on both linux/arm and freebsd/arm.
 	// 32-bit architectures
 	case sys.ARM:
-		// we use EABI on both linux/arm and freebsd/arm.
-		if Headtype == obj.Hlinux || Headtype == obj.Hfreebsd {
+		// we use EABI on linux/arm, freebsd/arm, netbsd/arm.
+		if Headtype == obj.Hlinux || Headtype == obj.Hfreebsd || Headtype == obj.Hnetbsd {
 			// We set a value here that makes no indication of which
 			// float ABI the object uses, because this is information
 			// used by the dynamic linker to compare executables and

src/runtime/defs1_netbsd_arm.go

@@ -104,6 +104,7 @@ type stackt struct {
 type timespec struct {
 	tv_sec  int64
 	tv_nsec int32
+	_       [4]byte // EABI
 }
 
 func (ts *timespec) set_sec(x int32) {
@@ -117,6 +118,7 @@ func (ts *timespec) set_nsec(x int32) {
 type timeval struct {
 	tv_sec  int64
 	tv_usec int32
+	_       [4]byte // EABI
 }
 
 func (tv *timeval) set_usec(x int32) {
@@ -129,10 +131,11 @@ type itimerval struct {
 }
 
 type mcontextt struct {
-	__gregs [17]uint32
-	__fpu   [4 + 8*32 + 4]byte // EABI
-	// __fpu [4+4*33+4]byte // not EABI
+	__gregs     [17]uint32
+	_           [4]byte   // EABI
+	__fpu       [272]byte // EABI
 	_mc_tlsbase uint32
+	_           [4]byte // EABI
 }
 
 type ucontextt struct {
@@ -140,6 +143,7 @@ type ucontextt struct {
 	uc_link     *ucontextt
 	uc_sigmask  sigset
 	uc_stack    stackt
+	_           [4]byte // EABI
 	uc_mcontext mcontextt
 	__uc_pad    [2]int32
 }
@@ -151,6 +155,7 @@ type keventt struct {
 	fflags uint32
 	data   int64
 	udata  *byte
+	_      [4]byte // EABI
 }
 
 // created by cgo -cdefs and then converted to Go