ARMv7 SIMD: Fix clang compatibility By design, clang only supports Unified Assembler Language (and not pre-UAL syntax): https://llvm.org/bugs/show_bug.cgi?id=23507 http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0473c/BABJIHGJ.html Thus, clang only supports the strbeq instruction and not streqb, but unfortunately some versions of GCC only support streqb. Go, go Gadget #ifdef... Based on https://github.com/mattsarett/libjpeg-turbo/commit/a82e63aac63f8fa3 95fa4caad4de6859623ee2e2 Closes #75