ld: remove MachoLoad limit

Fixes #1571.

R=ken2
CC=golang-dev
https://golang.org/cl/4443052

src/cmd/ld/macho.c

@@ -12,10 +12,10 @@
 
 static	int	macho64;
 static	MachoHdr	hdr;
-static	MachoLoad	load[16];
+static	MachoLoad	*load;
 static	MachoSeg	seg[16];
 static	MachoDebug	xdebug[16];
-static	int	nload, nseg, ndebug, nsect;
+static	int	nload, mload, nseg, ndebug, nsect;
 
 void
 machoinit(void)
@@ -43,10 +43,17 @@ newMachoLoad(uint32 type, uint32 ndata)
 {
 	MachoLoad *l;
 
-	if(nload >= nelem(load)) {
-		diag("too many loads");
+	if(nload >= mload) {
+		if(mload == 0)
+			mload = 1;
+		else
+			mload *= 2;
+		load = realloc(load, mload*sizeof load[0]);
+		if(load == nil) {
+			diag("out of memory");
 			errorexit();
 		}
+	}
 
 	if(macho64 && (ndata & 1))
 		ndata++;