[RFA] Delete another call to dwarf2read.c:decode_locdesc

[Jim Blandy]

Daniel Jacobowitz <drow@mvista.com> writes:
> The global variables set according to the DW_OP_frame_base are no longer
> used anywhere except decode_locdesc, and decode_locdesc is never called when
> we should expect a frame-relative object; see the updated comments in the
> patch below.  This function is now only used for member offsets, etc.;
> partial symbols (DW_TAG_variable only); and common blocks, which act as
> global variables.  The partial symbol case should either be eliminated or
> changed to use computed locations.  The common block case probably likewise.
> And the remaining cases expect constants.
> 
> So DW_OP_breg* and DW_OP_fbreg are dead wood at this point and can be
> removed from this function.  They're handled entirely in the LOC_COMPUTED
> support code.
> 
> These happened to be next on my campaign to whack global state from the
> dwarf2 reader; marching slowly down the file.  Tested on i386-linux/dwarf2.
> OK?

Superb!  Please commit.