Add TARGET_GCC_VERSION

Default to 4.6, but can overwritten to something else in
prebuilts/gcc/$os/$arch/$arch-linux-android*-$ver

Change-Id: I16f99d642b8ff8e831d392261a0c536041107051
[ARM] Extend the usage of TARGET_GCC_VERSION for gdb and arm-eabi-*.

In the future to upgrade the gcc version we just need to edit one
line in core/config.mk.

Change-Id: I01bb38c38f2388913bb7369aa4b2da480411dfbe
Export TARGET_GCC_VERSION as an env variable.

Have it referenced by the adbs tool to pick the specified toolchain.

Change-Id: I23df88946254a55d0749d6753e54559faf33e121
Enable O3 optimization

Change-Id: Ib9acf1d34701ebe45668d80a0b48651a1978f347

Conflicts:
	CleanSpec.mk
Allow configuration of gcc version used for build

You can override the default version by setting the value of
TARGET_GCC_VERSION in the BoardConfig.mk file. For example,
to select version 4.6, add the following:

TARGET_GCC_VERSION := 4.6

Change-Id: I10afb47b18c45e2b913b8af8f34cb98e5e96cbf2

Conflicts:
	core/config.mk

Conflicts:
	core/config.mk
Make gcc 4.6 default and non O3

* to use gcc 4.7 add TARGET_GCC_VERSION := 4.7 to your board config
* to use O3 add TARGET_USE_O3

Change-Id: Ia4a00023c84cc21122bdf1c116e51a179ccabd8c
Linaro CFlags opt

Change-Id: I145cda84bab3dc362142b2b2e5169e66a7d32f52
Extend support to toolchain 4.8

Change-Id: Id327da2b2968021887df930220447319e9178859
build: Add option to disable strict-aliasing optimizations

Change-Id: Ib924bed1e9695dbbe92662ea9a747de7af95b85e
build/core: Add option to disable C++11 bits

Change-Id: I2db0519cdafdd4b29975d65dc79886ac05bd6f7b