[llvm] [M68k] add 32 bit branch instrs and relaxations (PR #117371)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-m68k-linux-cross` running on `suse-gary-m68k-cross` while building `llvm` at step 5 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/27/builds/3331

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 5 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'LLVM :: MC/Disassembler/M68k/control.txt' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/stage1/bin/llvm-mc -disassemble -triple m68k /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt | /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/stage1/bin/FileCheck /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt
+ /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/stage1/bin/llvm-mc -disassemble -triple m68k /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt
+ /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/stage1/bin/FileCheck /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt
/var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt:23:11: warning: invalid instruction encoding
0x61 0xff 0x00 0x0f 0x00 0x01
          ^
/var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt:23:21: warning: invalid instruction encoding
0x61 0xff 0x00 0x0f 0x00 0x01
                    ^
/var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt:22:10: error: CHECK: expected string not found in input
# CHECK: bsr.l $f0001
         ^
<stdin>:9:12: note: scanning from here
 bsr.w $f01
           ^
<stdin>:10:2: note: possible intended match here
 bsr.b $ff
 ^

Input file: <stdin>
Check file: /var/lib/buildbot/workers/suse-gary-m68k-cross/clang-m68k-linux-cross/llvm/llvm/test/MC/Disassembler/M68k/control.txt

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            1:  .text 
            2:  bra $0 
            3:  jsr $0 
            4:  rts 
            5:  seq %d0 
            6:  sgt %d0 
            7:  nop 
            8:  bsr.b $1 
            9:  bsr.w $f01 
check:22'0                X error: no match found
           10:  bsr.b $ff 
check:22'0     ~~~~~~~~~~~
check:22'1      ?          possible intended match
>>>>>>

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/117371