Ports of lib9, libbio and libmach to Windows.

R=rsc
https://golang.org/cl/157159
diff --git a/src/libbio/binit.c b/src/libbio/binit.c
index 6eb7776..a7ade50 100644
--- a/src/libbio/binit.c
+++ b/src/libbio/binit.c
@@ -87,7 +87,7 @@
 	p += Bungetsize;	/* make room for Bungets */
 	size -= Bungetsize;
 
-	switch(mode&~(OCEXEC|ORCLOSE|OTRUNC)) {
+	switch(mode&~(ORCLOSE|OTRUNC)) {
 	default:
 		fprint(2, "Bopen: unknown mode %d\n", mode);
 		return Beof;
@@ -142,7 +142,7 @@
 	Biobuf *bp;
 	int f;
 
-	switch(mode&~(OCEXEC|ORCLOSE|OTRUNC)) {
+	switch(mode&~(ORCLOSE|OTRUNC)) {
 	default:
 		fprint(2, "Bopen: unknown mode %d\n", mode);
 		return 0;
@@ -154,7 +154,7 @@
 		break;
 
 	case OWRITE:
-		f = creat(name, 0666);
+		f = create(name, OWRITE|OTRUNC, 0666);
 		if(f < 0)
 			return 0;
 	}