V4: support calling constants.

Consider:
  function f() {
    var a;
    a();
  }

Here the constant propagation will propagate the value for a (undefined)
to the call site. This was not yet handled, resulting in Q_UNIMPLEMENTED
warnings when running a debug build.

Change-Id: I5f85f681d975b54df7a9e00bd5b50e6f4350139a
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
V4: teach the disassembler about VMUL, VCVT, and VCMP on ARM.

Change-Id: I2fee1d9d8c9b6437e6237388f2b0d93243fe601d
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>