dwarf2: Align relocation within .debug_line section

dwarf2: Align relocation within .debug_line section

All relocations specify a byte address.  As dwarf debug information is
organized in octets, some relocations may not be aligned.  While it
might be possible to define special relocations that operate at an
octet offset from their address, it's easier to ensure the relocations
are aligned by padding with "nop" statements.

In most dwarf sections this requirement is already fulfilled, only
relocations for symbol address within the .debug_line section can be
misaligned.

	* dwarf2dbg.c (out_set_addr): Align relocation within .debug_line.