message: Fix decoding switch opcodes
  Summary:
  By (search switch) the branch is encoded as a sint:
  > B: signed "branch" offset to table data pseudo-instruction
diff: @@ -2969,7 +2969,7 @@ class Opcode2B(Opcode):
  def __init__(self, inst, code_units):
  Opcode.__init__(self, inst)
  self.reg = inst.get_AA()
  - self.branch = inst.get_uint32(1)
  + self.branch = inst.get_sint32(1)
  def dump(self, f=sys.stdout):
  f.write('%s v%u, %8.8x // +%8.8x' % (self.get_name(), self.reg,
  @@ -2988,7 +2988,7 @@ class Opcode2C(Opcode):
  def __init__(self, inst, code_units):
  Opcode.__init__(self, inst)
  self.reg = inst.get_AA()
  - self.branch = inst.get_uint32(1)
  + self.branch = inst.get_sint32(1)
  def dump(self, f=sys.stdout):
  f.write('%s v%u, %8.8x // +%8.8x' % (self.get_name(), self.reg,
  