Force usage of dollar signs to circumvent arm-gcc balking at them.

R=rsc
APPROVED=rsc
DELTA=1  (1 added, 0 deleted, 0 changed)
OCL=29275
CL=29278

src/cmd/godefs/main.c

@@ -151,6 +151,7 @@ main(int argc, char **argv)
 
 	n = 0;
 	av[n++] = "gcc";
+	av[n++] = "-fdollars-in-identifiers";
 	av[n++] = "-S";	// write assembly
 	av[n++] = "-gstabs";	// include stabs info
 	av[n++] = "-o-";	// to stdout