[llvm] [Mips] Mark immediate branch macros as having delay slots (PR #217565)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-arm64-windows-msvc` running on `linaro-armv8-windows-msvc-04` while building `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/161/builds/12739

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM :: CodeGen/AArch64/GlobalISel/select-usubo.mir' FAILED ********************
Exit Code: 3221225539

Command Output (stdout):
--
# RUN: at line 2
c:\users\tcwg\llvm-worker\clang-arm64-windows-msvc\build\bin\llc.exe -verify-machineinstrs -mtriple aarch64-unknown-uknown -global-isel-abort=1 -run-pass=instruction-select C:\Users\tcwg\llvm-worker\clang-arm64-windows-msvc\llvm-project\llvm\test\CodeGen\AArch64\GlobalISel\select-usubo.mir -o - | c:\users\tcwg\llvm-worker\clang-arm64-windows-msvc\build\bin\filecheck.exe C:\Users\tcwg\llvm-worker\clang-arm64-windows-msvc\llvm-project\llvm\test\CodeGen\AArch64\GlobalISel\select-usubo.mir
# executed command: 'c:\users\tcwg\llvm-worker\clang-arm64-windows-msvc\build\bin\llc.exe' -verify-machineinstrs -mtriple aarch64-unknown-uknown -global-isel-abort=1 -run-pass=instruction-select 'C:\Users\tcwg\llvm-worker\clang-arm64-windows-msvc\llvm-project\llvm\test\CodeGen\AArch64\GlobalISel\select-usubo.mir' -o -
# .---command stdout------------
# | --- |
# |   ; ModuleID = 'C:\Users\tcwg\llvm-worker\clang-arm64-windows-msvc\llvm-project\llvm\test\CodeGen\AArch64\GlobalISel\select-usubo.mir'
# |   source_filename = "C:\\Users\\tcwg\\llvm-worker\\clang-arm64-windows-msvc\\llvm-project\\llvm\\test\\CodeGen\\AArch64\\GlobalISel\\select-usubo.mir"
# |   target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32"
# |   target triple = "aarch64-unknown-uknown"
# |   
# |   define void @usubo_s32() {
# |   entry:
# |     unreachable
# |   }
# |   
# |   define void @usubo_s64() {
# |   entry:
# |     unreachable
# |   }
# |   
# |   define void @usubo_s32_imm() {
# |   entry:
# |     unreachable
# |   }
# |   
# |   define void @usubo_s32_shifted() {
# |   entry:
# |     unreachable
# |   }
# |   
# |   define void @usubo_s32_neg_imm() {
# |   entry:
# |     unreachable
# |   }
# |   
# |   define void @usubo_arith_extended() {
# |   entry:
# |     unreachable
# |   }
# | ...
# | ---
# | name:            usubo_s32
# | alignment:       4
# | exposesReturnsTwice: false
# | legalized:       true
...

```

</details>

https://github.com/llvm/llvm-project/pull/217565