add linkage for writefile on darwin

SVN=127208

src/runtime/amd64_darwin.h

@@ -41,3 +41,5 @@ struct stat {	// really a stat64
 	uint32 st_gen;
  	int64 st_qspare[2];
 };
+
+#define	O_CREAT	0x0200

src/runtime/amd64_linux.h

@@ -38,3 +38,5 @@ struct stat {
 	struct timespec	st_mtime;   /* time of last modification */
 	struct timespec	st_ctime;   /* time of last status change */
 };
+
+#define	O_CREAT	0100

src/runtime/sys_amd64_linux.s

@@ -12,17 +12,10 @@ TEXT	sys·exit(SB),1,$0-8
 	SYSCALL
 	RET
 
-TEXT	sys·write(SB),1,$0-24
-	MOVL	8(SP), DI
-	MOVQ	16(SP), SI
-	MOVL	24(SP), DX
-	MOVL	$1, AX			// syscall entry
-	SYSCALL
-	RET
-
 TEXT	open(SB),1,$0-16
 	MOVQ	8(SP), DI
 	MOVL	16(SP), SI
+	MOVL	20(SP), DX
 	MOVL	$2, AX			// syscall entry
 	SYSCALL
 	RET
@@ -48,6 +41,22 @@ TEXT	read(SB),1,$0-24
 	SYSCALL
 	RET
 
+TEXT	write(SB),1,$0-24
+	MOVL	8(SP), DI
+	MOVQ	16(SP), SI
+	MOVL	24(SP), DX
+	MOVL	$1, AX			// syscall entry
+	SYSCALL
+	RET
+
+TEXT	sys·write(SB),1,$0-24
+	MOVL	8(SP), DI
+	MOVQ	16(SP), SI
+	MOVL	24(SP), DX
+	MOVL	$1, AX			// syscall entry
+	SYSCALL
+	RET
+
 TEXT	sys·rt_sigaction(SB),1,$0-32
 	MOVL	8(SP), DI
 	MOVQ	16(SP), SI

src/runtime/sys_file.c

@@ -59,7 +59,7 @@ sys·writefile(string filein, string textin, bool okout)
 
 	mcpy(namebuf, filein->str, filein->len);
 	namebuf[filein->len] = '\0';
-	fd = open(namebuf, 1|0x0200, 0644);  // open for write, create if non-existant (sic)
+	fd = open(namebuf, 1|O_CREAT, 0644);  // open for write, create if non-existant (sic)
 	if(fd < 0)
 		goto out;