cmd/*: add -d option to bison.

Without -d, bison doesn't generate y.tab.h.

R=rsc
CC=golang-dev
https://golang.org/cl/5685065

src/cmd/5a/Makefile

@@ -7,4 +7,4 @@ include ../../Make.dist
 install: y.tab.h
 
 y.tab.h: a.y
-	LANG=C LANGUAGE=en_US.UTF8 bison -v -y a.y
+	LANG=C LANGUAGE=en_US.UTF8 bison -d -v -y a.y

src/cmd/6a/Makefile

@@ -7,4 +7,4 @@ include ../../Make.dist
 install: y.tab.h
 
 y.tab.h: a.y
-	LANG=C LANGUAGE=en_US.UTF8 bison -v -y a.y
+	LANG=C LANGUAGE=en_US.UTF8 bison -d -v -y a.y

src/cmd/8a/Makefile

@@ -7,4 +7,4 @@ include ../../Make.dist
 install: y.tab.h
 
 y.tab.h: a.y
-	LANG=C LANGUAGE=en_US.UTF8 bison -v -y a.y
+	LANG=C LANGUAGE=en_US.UTF8 bison -d -v -y a.y

src/cmd/cc/Makefile

@@ -7,4 +7,4 @@ include ../../Make.dist
 install: y.tab.h
 
 y.tab.h: cc.y
-	LANG=C LANGUAGE=en_US.UTF8 bison -v -y a.y
+	LANG=C LANGUAGE=en_US.UTF8 bison -d -v -y a.y