[binutils] Force assembler to align code section size

[binutils] Force assembler to align code section size

Assembler pads code sections with NOPs, which is exactly what we need for NaCl.

This change introduces NOP padding at the end of the code section. Whitout this change, linker may add zero padding to code sections, which does not validate.

BUG=http://code.google.com/p/nativeclient/issues/detail?id=499
TEST=code sections in object files should be padded with NOPs at the end when needed

Committed: http://git.chromium.org/gitweb/?p=nacl-toolchain.git;a=commit;h=feaa0af

[pasko-google - do not use, 2010-12-21 17:55:50]

LGTM