build: work with GNU Make 3.82
Fix building on GNU Make 3.82 (caused by mixed implicit and normal
rules).
The issue was introduced in changeset 6110:ca0beac3b543.
R=rsc
CC=golang-dev
https://golang.org/cl/2100044
diff --git a/src/Make.pkg b/src/Make.pkg
index 4c46449..6c1ac7a 100644
--- a/src/Make.pkg
+++ b/src/Make.pkg
@@ -116,7 +116,10 @@
CGOPKGPATH=$(dir) cgo -- $(CGO_CFLAGS) $(CGOFILES)
# Ugly but necessary
-_cgo_gotypes.go _cgo_export.c _cgo_export.h %.cgo1.go %.cgo2.c: _cgo_defun.c
+_cgo_gotypes.go _cgo_export.c _cgo_export.h: _cgo_defun.c
+ @true
+
+%.cgo1.go %.cgo2.c: _cgo_defun.c
@true
%.cgo2.o: %.cgo2.c