vcc SUB type: store C symbols for struct vcl_sub and the function

We change the semantics of the rname and lname attributes of SUB
symbols: rname now is the name of the (struct vcl_sub), lname is the
cname, the name of the function to be called directly from VGC.

lib/libvcc/vcc_action.c

@@ -53,7 +53,7 @@ vcc_act_call(struct vcc *tl, struct token *t, struct symbol *sym)
 	if (sym != NULL) {
 		vcc_AddCall(tl, t0, sym);
 		VCC_GlobalSymbol(sym, SUB, "VGC_function");
-		Fb(tl, 1, "%s(ctx);\n", sym->rname);
+		Fb(tl, 1, "%s(ctx);\n", sym->lname);
 		SkipToken(tl, ';');
 	}
 }

lib/libvcc/vcc_parse.c

@@ -251,7 +251,7 @@ vcc_ParseFunction(struct vcc *tl)
 		VCC_GlobalSymbol(sym, SUB, "VGC_function");
 		p = vcc_NewProc(tl, sym);
 		p->name = t;
-		VSB_printf(p->cname, "%s", sym->rname);
+		VSB_printf(p->cname, "%s", sym->lname);
 	} else if (p->method == NULL) {
 		VSB_printf(tl->sb, "Subroutine '%s' redefined\n", sym->name);
 		vcc_ErrWhere(tl, t);

lib/libvcc/vcc_symb.c

@@ -471,6 +471,14 @@ VCC_GlobalSymbol(struct symbol *sym, vcc_type_t type, const char *pfx)
 	VSB_printf(vsb, "%s_", pfx);
 	VCC_PrintCName(vsb, sym->name, NULL);
 	AZ(VSB_finish(vsb));
+	sym->lname = strdup(VSB_data(vsb));
+	if (type == SUB) {
+		VSB_destroy(&vsb);
+		vsb = VSB_new_auto();
+		AN(vsb);
+		VSB_printf(vsb, "sub_%s", sym->lname);
+		AZ(VSB_finish(vsb));
+	}
 	sym->rname = strdup(VSB_data(vsb));
 	AN(sym->rname);
 	VSB_destroy(&vsb);