ota_from_target_files: Validate signatures after possible data wipe

If the data is being wiped, we want to validate the signature after
this step. This is also a good check that the data wipe succeeded.

Change-Id: Iaecfddfb2010944de0c97e7bb21d8e581f20deec

Conflicts:

	tools/releasetools/ota_from_target_files
Restore VerifySignature to edify_generator

Change-Id: If5fedb9b1b98394c0bee3efc3523d0e2f9499887
vanirified (cflag no-op on most devices): Apply correct, optimized mfpu compiler flag for ARMv7-A Cortex CPUs

For those ARMv7-A Cortex CPUs that can handle VFPv4 floating point,
We can set "-mfpu=neon-vfpv4" instead of generic "-mfpu=neon"
to gain extra performance improvements.

References :
 - GCC		: https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html
 - Cortex A15	: http://www.arm.com/products/processors/cortex-a/cortex-a15.php
 - Cortex A9	: http://www.arm.com/products/processors/cortex-a/cortex-a9.php
 - Cortex A8	: http://www.arm.com/products/processors/cortex-a/cortex-a8.php
 - Cortex A7	: http://www.arm.com/products/processors/cortex-a/cortex-a7.php
 - Cortex A5	: http://www.arm.com/products/processors/cortex-a/cortex-a5.php

Change-Id: Id8b1a251234014ecf7ffbc1ae14455ed1726e028
Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>

Conflicts:

	core/combo/arch/arm/armv7-a-neon.mk
Disable canonical prefixes of system headers

GCC know a few pre-defined paths (relative to its location) to
search for headers, libraries, program, etc.  By default GCC prefixes
its own path(argv[0]) and calls realpath() which result in absolute
path with all symlink, . and .. removed.

It's usually good to have canonicalised paths, but absolute paths
in *.d file can cause unnecessary relinking when stale entries
in ccache cache hit

Add -no-canonical-prefixes (gcc>=4.6) and
-fno-canonical-system-headers (gcc>4.6) to disable realpath() on
prefixed paths

NOTE: This commit also helps reduse incorrect PATHS and
linker errors from clang, especially msm prebuilt clang

Change-Id: I58d739e61fb013015fb05a9c98b2132b307f915a
Signed-off-by: Bart Monhemius <bart4524@gmail.com>