Prepare upcoming GCC 4.8 release.

o Add -Wno-unused-parameter -Wno-unused-but-set-parameter to suppress
  new warnings.
o Define GCC_COLORS to enable colorful diagnostic messages.

Change-Id: Icbd62300b0e6f39d4e514edec2431a06b4d72421
(cherry picked from internal commit ccd8e6082b5b1e519a75068fa6c887a1a85b53c4)

Conflicts:
	core/combo/TARGET_linux-arm.mk
	envsetup.sh
Link libgcc.a before shared libraries (especially libc.so).

BUG: 8247455
Change-Id: Ia8816536ca95a7084e80c7f425f81658afea9609
Add extra libgcc.a only for unbundled build.

We can save some space for platform build with this.
Previously an extra libgcc.a was put before libc.so so libraries built
against new platform can run on old platforms. This is needed only for
unbundled build.

Bug: 8805022
Bug: 8247455

Change-Id: I3c3e0092b06ec3804659d5cae048d29e0d2bf7ad
Duplicate libgcc.a in front of *so

Also see 6c7bc550adb917157a9f53ebf8898110e37294b2

Change-Id: Iade6cd6b40cd4840a148098e1d8fc7a0c97e2f66