* config/tc-xtensa.c: Warning fixes throughout.
(xtensa_fetch_width): Change to unsigned.
(assemble_nop, xtensa_find_unaligned_branch_targets,
xtensa_find_unaligned_loops, xg_assemble_vliw_tokens,
is_narrow_branch_guaranteed_in_range, xtensa_fix_close_loop_end_frags,
min_bytes_to_other_loop_end, unrelaxed_frag_min_size,
unrelaxed_frag_max_size, xtensa_fix_short_loop_frags,
count_insns_to_loop_end, unrelaxed_frag_min_insn_count,
get_text_align_max_fill_size, get_text_align_nop_count,
get_text_align_nth_nop_size, get_noop_aligned_address,
get_aligned_diff, convert_frag_align_next_opcode,
convert_frag_immed_finish_loop, xtensa_create_property_segments,
xtensa_create_xproperty_segments, xt_block_aligned_size): Clean up
types, avoiding size_t and using offsetT and addressT appropriately.
(get_text_align_power): Clean up types. Avoid incorrect bound.
(get_text_align_fill_size): Clean up types. Restructure for clarity.