Attached is the latest version of the patch.

I implemented the complaint, and then reverted it, for reasons that
I explained in the added comment inside the new attr_value_as_address
function. Basically, I don't want to be doing extra work as well as
pessimize this function's number of arguments just for a very rare
case of broken compiler.

The added comment should make it clear that there is no guaranty of
correct behavior, though.

gdb/ChangeLog:

        * dwarf2read.c (attr_value_as_address): New function.
        (dwarf2_find_base_address, read_call_site_scope): Use
        attr_value_as_address in place of DW_ADDR.
        (dwarf2_get_pc_bounds): Use attr_value_as_address to get
        the low and high addresses.  Slight rework of the handling
        of the high pc being a constant form, and limit it to
        DWARF verson 4 or higher.
        (dwarf2_record_block_ranges): Likewise.
        (read_partial_die): Likewise.
        (new_symbol_full): Use attr_value_as_address in place of DW_ADDR.

gdb/testsuite/ChangeLog:

        * gdb.dwarf2/dw2-abs-hi-pc-hello-dbg.S: New file.
        * gdb.dwarf2/dw2-abs-hi-pc-hello.c: New file.
        * gdb.dwarf2/dw2-abs-hi-pc-world-dbg.S: New file.
        * gdb.dwarf2/dw2-abs-hi-pc-world.c: New file.
        * gdb.dwarf2/dw2-abs-hi-pc.c: New file.
        * gdb.dwarf2/dw2-abs-hi-pc.exp: New file.

Tested on x86_64-linux.

-- 
Joel