gdbhooks.py: Reorganize, to support regex matching and typedefs

gdbhooks.py: Reorganize, to support regex matching and typedefs

	* gdbhooks.py (GdbSubprinter.__init__): Drop str_type_ field.
	(GdbSubprinter.handles_type): New.
	(GdbSubprinterTypeList): New subclass of GdbSubprinter.
	(GdbSubprinterRegex): New subclass of GdbSubprinter.
	(GdbPrettyPrinters.add_printer): Remove in favor of...
	(GdbPrettyPrinters.add_printer_for_types): ...this new method
	and...
	(GdbPrettyPrinters.add_printer_for_regex): ...this other new method.
	(GdbPrettyPrinters.__call__): Update search for subprinter
	to use handles_type method.
	(build_pretty_printer): Update registration of subprinters to
	use the new API above, supporting multiple spelling of each type,
	and allowing for future regex-based subprinters.

From-SVN: r205085