Run crash cases in deterministic order

Add segfault crash case crash-20-segfault-in-llvm-mcassembler-computefragmentsize.c

Add crash case crash-19-unable-to-encode-mcoperand.c

This breaks suite/regress/x64_nasm_default_rel.py.

Limit value of local labels (fix #82).

arm: propagate error from ARMAsmParser::validateTargetOperandClass(). this fixes crash-16-expression-value-must-be-representable-in-32-bits.c

propagate error from APFloat::convertFromDecimalString(). this fixes crash-06-exponent-has-no-digits-in-apfloat-line-126.c

mips: propagate error from MipsAsmParser::processInstruction() back to ks_asm(). this fixes issue #110

Fixed rel address issues for SystemZ (Issue #108)

Fixed relative address encoding for branches at ARM and Thumb mode.
Also added correct checks for out of range branches. Finally removed
a check for Thumb mode that would never succeed.

allow kstool input from stdin

Add two assertion failure crashers.

Added regress test for jumps to absolute addresses