Backport upstream assember fix and disassembler fix.

Backport upstream fix in disassembler to handle mapping
symbol properly.
http://www.cygwin.com/ml/binutils-cvs/2009-03/msg00242.html

Backport upstream assembler fix.
This backports the following upstream fix for forward references
http://sourceware.org/ml/binutils-cvs/2010-09/msg00204.html

Change-Id: I2dc54d9cbe09a793a50b7ace4628c0e120616a32