runtime: cleanup amd64p32 memmove and memclr file organization

Move memclr to a separate file to make it consistent
with other platforms asm function to file organization.

Remove nacl from the memmove filename as the implementation
is generic for the amd64p32 platform even if currently only
nacl is supported for amd64p32.

Change-Id: I8930b76da430a5cf2664801974e4f5185fc0f82f
Reviewed-on: https://go-review.googlesource.com/61031
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>

src/runtime/asm_amd64p32.s

@@ -559,24 +559,6 @@ TEXT runtime·stackcheck(SB), NOSPLIT, $0-0
 	MOVL	0, AX
 	RET
 
-TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-8
-	MOVL	ptr+0(FP), DI
-	MOVL	n+4(FP), CX
-	MOVQ	CX, BX
-	ANDQ	$3, BX
-	SHRQ	$2, CX
-	MOVQ	$0, AX
-	CLD
-	REP
-	STOSL
-	MOVQ	BX, CX
-	REP
-	STOSB
-	// Note: we zero only 4 bytes at a time so that the tail is at most
-	// 3 bytes. That guarantees that we aren't zeroing pointers with STOSB.
-	// See issue 13160.
-	RET
-
 TEXT runtime·getcallerpc(SB),NOSPLIT,$8-12
 	MOVL	argp+0(FP),AX		// addr of first arg
 	MOVL	-8(AX),AX		// get calling pc

src/runtime/memclr_amd64p32.s

@@ -0,0 +1,23 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+TEXT runtime·memclrNoHeapPointers(SB),NOSPLIT,$0-8
+	MOVL	ptr+0(FP), DI
+	MOVL	n+4(FP), CX
+	MOVQ	CX, BX
+	ANDQ	$3, BX
+	SHRQ	$2, CX
+	MOVQ	$0, AX
+	CLD
+	REP
+	STOSL
+	MOVQ	BX, CX
+	REP
+	STOSB
+	// Note: we zero only 4 bytes at a time so that the tail is at most
+	// 3 bytes. That guarantees that we aren't zeroing pointers with STOSB.
+	// See issue 13160.
+	RET