[XCore] Remove '-' from back branch asm syntax.

Instead operands are treated as negative immediates
where the sign bit is implicit in the instruction
encoding.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181151 91177308-0d34-0410-b5e6-96231b3b80d8
[XCore] Add BLRB instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181152 91177308-0d34-0410-b5e6-96231b3b80d8
[XCore] Rename calltarget -> pcrel_imm.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181153 91177308-0d34-0410-b5e6-96231b3b80d8
[XCore] Update LDAP to use pcrel_imm.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181154 91177308-0d34-0410-b5e6-96231b3b80d8
[XCore] Add LDAPB instructions.

With the change the disassembler now supports the XCore ISA in its
entirety.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181155 91177308-0d34-0410-b5e6-96231b3b80d8