Use bitpos and type to lookup a gdb.Field object when its name is 'None'.

	PR python/15464
	PR python/16113
	* valops.c (value_struct_elt_bitpos): New function
	* py-type.c (convert_field): Set 'name' attribute of a gdb.Field
	object to 'None' if the field name is an empty string ("").
	* python/py-value.c (valpy_getitem): Use 'bitpos' and 'type'
	attribute to look for a field when 'name' is 'None'.
	(get_field_type): New function

	testsuite/
	* gdb.python/py-type.c: Enhance test case.
	* gdb.python/py-value-cc.cc: Likewise
	* gdb.python/py-type.exp: Add new tests.
	* gdb.python/py-value-cc.exp: Likewise
Add missing empty line after declarations in "if" block (py-type.c).

This patch fixes a small coding-style violation...

gdb/ChangeLog:

        * python/py-type.c (convert_field): Add missing empty line
        after declarations.
Fix small style violation in py-value.c:get_field_type

gdb/ChangeLog:

        * python/py-value.c (get_field_type): Remove unnecessary curly
        braces for single-statement if block.

Tested on x86_64-linux.
* dwarf2read.c (open_and_init_dwp_file): Use pulongest to print uint32_t.
Automatic date update in version.in