Centralize yacc interface names remapping (yyparse, yylex, yyerror, etc)

Centralize yacc interface names remapping (yyparse, yylex, yyerror, etc)

This factors out all the yy-variables remapping to a single file,
instead of each parser having to do the same, with different prefixes.

With this, a parser just needs to define the prefix they want and
include yy-remap.h, which does the dirty job.

Note this renames the c_error, ada_error, etc. functions.  Writing the
remapping pattern as:

 #define yyerror GDB_YY_REMAP (error)

instead of:

 #define yyerror GDB_YY_REMAP (yyerror)

would have avoided the renaming.  However, that would be problematic
if we have a macro 'foo' in scope, when we write:

 #define yyfoo GDB_YY_REMAP (foo)

as that would expand 'foo'.

The c_yyerror etc. naming end ups indicating that this is a yacc
related function more clearly, so feels like a good change, anyway.

gdb/ChangeLog:
2016-04-22  Pedro Alves  <palves@redhat.com>

	* ada-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* ada-lang.c (ada_language_defn): Adjust.
	* ada-lang.h (ada_error): Rename to ...
	(ada_yyerror): ... this.
	* c-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* c-lang.c (c_language_defn, cplus_language_defn)
	(asm_language_defn, minimal_language_defn): Adjust.
	* c-lang.h (c_error): Rename to ...
	(c_yyerror): ... this.
	* d-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* d-lang.c (d_language_defn): Adjust.
	* d-lang.h (d_error): Rename to ...
	(d_yyerror): ... this.
	* f-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* f-lang.c (f_language_defn): Adjust.
	* f-lang.h (f_error): Rename to ...
	(f_yyerror): ... this.
	* go-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* go-lang.c (go_language_defn): Adjust.
	* go-lang.h (go_error): Rename to ...
	(go_yyerror): ... this.
	* jv-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* jv-lang.c (java_language_defn): Adjust.
	* jv-lang.h (java_error): Rename to ...
	(java_yyerror): ... this.
	* m2-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* m2-lang.c (m2_language_defn): Adjust.
	* m2-lang.h (m2_error): Rename to ...
	(m2_yyerror): ... this.
	* objc-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* objc-lang.c (objc_language_defn): Adjust.
	* opencl-lang.c (opencl_language_defn): Adjust.
	* p-exp.y: Remove all yy symbol remappings.
	(GDB_YY_REMAP_PREFIX): Define.
	Include "yy-remap.h".
	* p-lang.c (pascal_language_defn): Adjust.
	* p-lang.h (pascal_error): Rename to ...
	(pascal_yyerror): ... this.
	* yy-remap.h: New file.