godefs: better handling of enums

Fixes #432.

R=r, r2
CC=golang-dev
https://golang.org/cl/3869043

src/cmd/godefs/main.c

@@ -373,6 +373,8 @@ Continue:
 				prefix = prefixlen(t);
 			for(j=0; j<t->nf; j++) {
 				f = &t->f[j];
+				if(f->type->kind == 0)
+					continue;
 				// padding
 				if(t->kind == Struct || lang == &go) {
 					if(f->offset%8 != 0 || f->size%8 != 0) {

src/cmd/godefs/stabs.c

@@ -363,13 +363,22 @@ parsedef(char **pp, char *name)
 				return nil;
 			}
 
+			while(f->type->kind == Typedef)
+				f->type = f->type->type;
+			if(f->type->kind == 0 && f->size <= 64 && (f->size&(f->size-1)) == 0) {
+				// unknown type but <= 64 bits and bit size is a power of two.
+				// could be enum - make Uint64 and then let it reduce
+				tt = emalloc(sizeof *tt);
+				*tt = *f->type;
+				f->type = tt;
+				tt->kind = Uint64;
+			}
+
 			// rewrite
 			//	uint32 x : 8;
 			// into
 			//	uint8 x;
 			// hooray for bitfields.
-			while(f->type->kind == Typedef)
-				f->type = f->type->type;
 			while(Int16 <= f->type->kind && f->type->kind <= Uint64 && kindsize[f->type->kind] > f->size) {
 				tt = emalloc(sizeof *tt);
 				*tt = *f->type;