Add new command line options --cflags_for_target and --cxxflags_for_target, and pass them into emerge.

Tested:
./build_tc.py -b x86-alex -c ~/cros2/ --cxxflags_for_target="-Wunused-label" -g ~/gcc47cros/
And look at the output to ensure -Wunused-label is actually used.

PRESUBMIT=passed
R=shenhan,yunlian,llozano,asharif,cmtice
CC=c-compiler-chrome
APPROVED=llozano
DELTA=12  (12 added, 0 deleted, 0 changed)
OCL=65833-p2
RCL=65854-p2
RDATE=2013/02/13 15:15:01


P4 change: 42807590
1 file changed
tree: 3106cbd12cd7726e46d55ee733ec215968d905a0
  1. .git5_specs/
  2. v14/