[PATCH 10/11] Handle bitfields for CodeView

[PATCH 10/11] Handle bitfields for CodeView

Translates structure members with DW_AT_data_bit_offset set in DWARF
into LF_BITFIELD symbols.

gcc/
	* dwarf2codeview.cc (struct codeview_custom_type): Add lf_bitfield to
	union.
	(write_lf_bitfield): New function.
	(write_custom_types): Call write_lf_bitfield.
	(create_bitfield): New function.
	(get_type_num_struct): Handle bitfields.
	* dwarf2codeview.h (LF_BITFIELD): Define.