* Define CMAKE_ARM_COMPILER automatically (#469)
Makes use of CMAKE_SYSTEM_PROCESSOR to detect whether compilation is happening for an ARM architecture.
* Use the correct guard for specifying msse2 compiler flags.
Bruteforce and conversions were only checking against ANDROID which was not sufficient for ARM Linux builds.
* Remove redundant uses of the msse2 compiler flag.
* Globally set -msse2 for x86/amd64 gcc, Apple and Clang builds.
This is a change in behaviour. Prior to this commit, msse2 was only set for bruteforce and conversions.
msse and mfpmath=sse were already set globally prior to this change.