configure.ac: Skip C if explicitly selected.

configure.ac: Skip C if explicitly selected.

toplevel/
	* configure.ac: Skip C if explicitly selected.
	* configure: Regenerate.

gcc/
	* configure.ac: Remove special gtfiles case for C.
	* configure: Regenerate.
	* Makefile.in: Remove C front-end hooks and build hooks that
	will be picked up from c/Make-lang.in now.
	Add tree-mudflap to C_COMMON_OBJS.
	* gengtype.c (files_rules): Adjust gt-files for c/c-decl.c.
	* config/vms/vms.c: Look for c-tree.h in c/.
	* doc/gty.texi: Remove reference to c-config-lang.in.
	* doc/sourcebuild.texi: Document the c/ subdirectory.

c/
	* Make-lang.in: New file, rules migrated from gcc/Makefile.in
	and add language Makefile hooks.
	* config-lang.in: New file.
	* c-config-lang.in: Moved from gcc/config-lang.in to here, and
	add the required "normal" config-lang.in rules.
	* c-lang.h: Moved from gcc/ to here.
	* c-tree.h: Likewise.
	* c-objc-common.c: Likewise.
	* c-objc-common.h: Likewise.
	* c-typeck.c: Likewise.
	* c-convert.c: Likewise.
	* c-lang.c: Likewise.
	* c-aux-info.c: Likewise.
	* c-errors.c: Likewise.
	* gccspec.c: Likewise.
	* c-decl.c: Likewise.  Include gt-c-c-decl.h, not gt-c-decl.h.
	* c-parser.c: Likewise.  Include gt-c-c-parser.h, not gt-c-parser.h.

c-family/
	* cppspec.c: Moved from gcc/ to here.

objc/
	* Make-ang.in: Adjust for move of C front-end files.
	* config-lang.in: Likewise.
	* objc-encoding.c: Look for cp-tree.h in cp/, and for c-tree.h
	and c-lang.h in c/.
	* objc-runtime-shared-support.c: Likewise.
	* objc-next-runtime-abi-01.c: Likewise.
	* objc-next-runtime-abi-02.c: Likewise.
	* objc-gnu-runtime-abi-01.c: Likewise.
	* objc-act.c: Likewise.
	* objc-lang.c: Likewise.

cp/
	* Make-lang.in: Remove tree-mudflap.o from CXX_AND_OBJCXX_OBJS.

From-SVN: r189080