[clang] [llvm] [llvm-objcopy][libObject] Add RISC-V big-endian support (PR #146913)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-expensive-checks-ubuntu` running on `as-builder-4` while building `clang,llvm` at step 7 "test-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/187/builds/8205

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

```
Step 7 (test-check-all) failure: Test just built components: check-all completed (failure)
******************** TEST 'LLVM :: MC/Mips/reloc-directive.s' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
/home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips-unknown-linux < /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s -show-encoding -target-abi=o32      | /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=ASM /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s # RUN: at line 1
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips-unknown-linux -show-encoding -target-abi=o32
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=ASM /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s
/home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips64-unknown-linux < /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s -show-encoding -target-abi=n32      | /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=ASM /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s # RUN: at line 3
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips64-unknown-linux -show-encoding -target-abi=n32
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=ASM /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s
/home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips64-unknown-linux < /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s -show-encoding -target-abi=n64      | /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=ASM /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s # RUN: at line 5
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips64-unknown-linux -show-encoding -target-abi=n64
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=ASM /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s
/home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips-unknown-linux < /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s -show-encoding -target-abi=o32      -filetype=obj | /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-readobj --sections --section-data -r - |      /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=OBJ-O32 /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s # RUN: at line 7
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-mc -triple mips-unknown-linux -show-encoding -target-abi=o32 -filetype=obj
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/FileCheck -check-prefix=OBJ-O32 /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s
+ /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/build/bin/llvm-readobj --sections --section-data -r -
/home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s:137:17: error: OBJ-O32-NEXT: is not on the line after the previous match
# OBJ-O32-NEXT: 0x88 R_MIPS_NONE -
                ^
<stdin>:235:2: note: 'next' match was here
 0x88 R_MIPS_NONE -
 ^
<stdin>:233:25: note: previous match ended here
 0x84 R_MICROMIPS_JALR -
                        ^
<stdin>:234:1: note: non-matching line after previous match is here
 0x88 R_MIPS_16 -
^

Input file: <stdin>
Check file: /home/buildbot/worker/as-builder-4/ramdisk/expensive-checks/llvm-project/llvm/test/MC/Mips/reloc-directive.s

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

Input was:
<<<<<<
          .
          .
          .
        230:  0x78 R_MICROMIPS_TLS_TPREL_HI16 - 
        231:  0x7C R_MICROMIPS_TLS_TPREL_LO16 - 
        232:  0x80 R_MIPS_JALR - 
        233:  0x84 R_MICROMIPS_JALR - 
        234:  0x88 R_MIPS_16 - 
        235:  0x88 R_MIPS_NONE - 
next:137      !~~~~~~~~~~~~~~~~~  error: match on wrong line
        236:  0x88 R_MIPS_32 - 
        237:  0x88 R_MIPS_64 - 
...

```

</details>

https://github.com/llvm/llvm-project/pull/146913