build/core: Add linaro_compilerchecks.mk

Add linaro_compilerchecks.mk, allowing to run some checks on the
compiler version and supported flags before setting them

Change-Id: I96e1277e74c0ea3457677bef39644aaece01f653
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
Compiler customizations

Available BoardConfig options, linaro 4.6 is default
	DEV_GOOGLE_BUILD := 1 (Google's 4.7.x gcc toolchain)
	GOOGLE_BUILD := 1 (Google's 4.6.x gcc toolchain)
	DEV_LINARO_BUILD := 1 (Linaro's 4.7.x toolchain)

Change-Id: If9cae41a6d62a98ac066dbe601318427b7c353fd

compiler customizations: always use Linaro 4.7 toolchanin to build the kernel

Change-Id: Ie8a033717f93d4b5f6066f59a6eca4c45b894cdc

Compiler checks:  Remove DEV_GOOGLE_BUILD option since it's

pointless to have two 4.7 toolchains.  Linaro's works just fine.

Use Google's toolchains by default

Use Google's 4.7 toolchain by default

Update all toolchain checks to use 4.7
Extend dalvik flags to gcc 4.8
Build:  Add a variable to enable GNU gcc 4.8 toolchain building.

This is now default for grouper/tilapia ROM/kernel when using the
build scripts.

Signed-off-by: Paul Beeler <sparksco@gmail.com>
Fix typos:  Use 4.7 for all toolchains unless overrided by a BoardConfg

option
Revert "Build:  Add a variable to enable GNU gcc 4.8 toolchain building."

This reverts commit e20ab33ee3c8505af8eee7030d5ee26ecdef6a5c.

Signed-off-by: Paul Beeler <sparksco@gmail.com>
Compiler options:  Add SaberMod GCC 4.8 androideabi as a BoardConfig

option.  To enable add USE_SABERMOD_ANDROIDEABI_48 := true
to your BoardConfig.mk of a SaberMod supported device

Signed-off-by:  Paul Beeler <sparksco@gmail.com>
Add usage of GCC 4.8 SaberMod toolchain to a special branch