New field 'la_natural_name' in struct language_defn

New field 'la_natural_name' in struct language_defn

This patch adds "natural name" of each supported languages, which will
be used by the next patch.

gdb:

2013-11-07  Yao Qi  <yao@codesourcery.com>

	* language.h (struct language_defn) <la_natural_name>: New field.
	* ada-lang.c (ada_language_defn): Initialize field 'la_natural_name'.
	* c-lang.c (c_language_defn): Likewise.
	(cplus_language_defn, asm_language_defn): Likewise.
	* d-lang.c (d_language_defn): Likewise.
	* f-lang.c (f_language_defn): Likewise.
	* go-lang.c (go_language_defn): Likewise.
	* jv-lang.c (java_language_defn): Likewise.
	* language.c (unknown_language_defn ): Likewise.
	(auto_language_defn): Likewise.
	* m2-lang.c (m2_language_defn): Likewise.
	* objc-lang.c (objc_language_defn): Likewise.
	* opencl-lang.c (opencl_language_defn): Likewise.
	* p-lang.c (pascal_language_defn): Likewise.