Defined locations of parser files in config.h instead of Makefile.

acinclude.m4

@@ -0,0 +1,13 @@
+dnl BISON_DEFINE_FILE(VARNAME, FILE)
+dnl Defines (with AC_DEFINE) VARNAME to the expansion of the FILE
+dnl variable, expanding ${prefix} and such.
+dnl Example: BISON_DEFINE_FILE(DATADIR, datadir)
+dnl By Alexandre Oliva <oliva@dcc.unicamp.br>
+AC_DEFUN(BISON_DEFINE_FILE, [
+        ac_expanded=`(
+            test "x$prefix" = xNONE && prefix="$ac_default_prefix"
+            test "x$exec_prefix" = xNONE && exec_prefix="${prefix}"
+            eval echo \""[$]$2"\"
+        )`
+        AC_DEFINE_UNQUOTED($1, "$ac_expanded")
+])