[PATCH] gdb: small cleanups in dwarf2_psymtab constructors
I noticed that only one of the two dwarf2_psymtab constructors are
actually used. The one that is used accepts an `addr` parameter (the
base text offset), but its sole caller passes a constant, 0. We want to
keep calling the three-arguments standard_psymtab constructor form,
however, since it differs from the two-arguments form in subtle ways.
Also, I believe the dwarf2_per_cu_data associated to the created
dwarf2_psymtab should be passed as a constructor argument. That will
help me in a future patchset, to convince myself that the `per_cu_data`
field can't be NULL.
So this patch:
- Removes the two-parameters constructor of dwarf2_psymtab, as it is
- Removes the `addr` parameter of the remaining constructor, passing 0
directly to the base class' constructor.
- Adds a `per_cu` parameter, to assign the `per_cu_data` field at