Fixed a few bugs in ARM disassembly (blx immediate needed alignment when transitioning to arm, thumb pop can't have sp in it)

* added a test file to suite for testing invalid and valid instruction sequences

* fixed and added a test for a thumb-2 invalid sequence that was incorrectly allowed before these changes (pop.w with sp argument included)
* fixed and added a test for a blx from thumb to ARM that had its immediate argument incorrect (misaligned)

* eliminated some warnings by explicitly casting so I could turn on
  treat warnings as errors locally

General notes:
*  probably worth turning on treat all warnings as errors in the msvc project files, had a subtle bug that resulted from a missing declaration causing differences in dll and static compilation modes

( code was working incorrectly in dll form because of missing declaration in arch/ARM/ARMMapping.h for new function ARM_blx_to_arm_mode. Something about the linking was confusing ld when making the dll, and the resulting offsets were wonky (e.g. the added ble test would show up as #0x1fc instead of #0x1fe like it should have )

* the invalid pop was being treated as a soft fail which then gets coerced
  to a success because it is != MCDisassembler_Fail in Thumb_getInstruction
  what are the semantics of a soft fail? Maybe we should be able to set up
  whether or not we want a soft fail to be a real fail in the csh struct?

Here is expected output from the test_arm_regression.c file:

    Should be invalid
    -----------------
    Thumb bde81eff: invalid thumb2 pop because sp used and because both pc and
     lr are present at the same time
        SUCCESS: invalid
    
    Should be valid
    ---------------
    Thumb 00f026e8 @ 0x0352: thumb2 blx with misaligned immediate
        0x352:      blx     #0x3a0
            op_count: 1
                    operands[0].type: IMM = 0x3a0
        SUCCESS: valid
    Thumb 05dd @ 0x01f0: thumb b cc with thumb-aligned target
        0x1f0:      ble     #0x1fe
            op_count: 1
                    operands[0].type: IMM = 0x1fe
            Code condition: 14
        SUCCESS: valid