Convert yacc to a single RuleBuilder rule

So that <module>/gen/yacc/... is (re)created by a single rule, previous
files are removed, and location.hh is in the build graph when it is
produced.

Test: treehugger
Change-Id: I2f6e47ea07f315e10ae1cb8ad50697e7123d0285
diff --git a/cc/builder.go b/cc/builder.go
index 65369d6..87db645 100644
--- a/cc/builder.go
+++ b/cc/builder.go
@@ -239,7 +239,6 @@
 	cppFlags        string
 	ldFlags         string
 	libFlags        string
-	yaccFlags       string
 	tidyFlags       string
 	sAbiFlags       string
 	yasmFlags       string
@@ -262,6 +261,8 @@
 	proto            android.ProtoFlags
 	protoC           bool
 	protoOptionsFile bool
+
+	yacc *YaccProperties
 }
 
 type Objects struct {