[llvm] [MachO] Refine alias n_desc flag ownership (name flags from alias, not aliasee) (PR #212001)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 138982 tests passed
* 3585 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### LLVM
<details>
<summary>LLVM.MC/MachO/lto-set-conditional.s</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
c:\_work\llvm-project\llvm-project\build\bin\llvm-mc.exe -filetype=obj -triple i386-apple-darwin9 < C:\_work\llvm-project\llvm-project\llvm\test\MC\MachO\lto-set-conditional.s | c:\_work\llvm-project\llvm-project\build\bin\llvm-readobj.exe --symbols - | c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe C:\_work\llvm-project\llvm-project\llvm\test\MC\MachO\lto-set-conditional.s
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\llvm-mc.exe' -filetype=obj -triple i386-apple-darwin9
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\llvm-readobj.exe' --symbols -
# note: command had no output on stdout or stderr
# executed command: 'c:\_work\llvm-project\llvm-project\build\bin\filecheck.exe' 'C:\_work\llvm-project\llvm-project\llvm\test\MC\MachO\lto-set-conditional.s'
# .---command stderr------------
# | C:\_work\llvm-project\llvm-project\llvm\test\MC\MachO\lto-set-conditional.s:26:15: error: CHECK-NEXT: expected string not found in input
# | # CHECK-NEXT: NoDeadStrip
# |               ^
# | <stdin>:22:9: note: scanning from here
# |  Flags [ (0x0)
# |         ^
# | <stdin>:30:20: note: possible intended match here
# |  RefType: UndefinedNonLazy (0x0)
# |                    ^
# | 
# | Input file: <stdin>
# | Check file: C:\_work\llvm-project\llvm-project\llvm\test\MC\MachO\lto-set-conditional.s
# | 
# | -dump-input=help explains the following input dump.
# | 
# | Input was:
# | <<<<<<
# |            .
# |            .
# |            .
# |           17:  Symbol { 
# |           18:  Name: b (13) 
# |           19:  Type: Section (0xE) 
# |           20:  Section: __text (0x1) 
# |           21:  RefType: UndefinedNonLazy (0x0) 
# |           22:  Flags [ (0x0) 
# | next:26'0            {         search range start (exclusive)
# | next:26'1                      error: no match found in search range
# |           23:  ] 
# |           24:  Value: 0x1 
# |           25:  } 
# |           26:  Symbol { 
# |           27:  Name: c (11) 
# |           28:  Type: Section (0xE) 
# |           29:  Section: __text (0x1) 
# |           30:  RefType: UndefinedNonLazy (0x0) 
# | next:26'2                        ?               possible intended match
# |           31:  Flags [ (0x0) 
# |           32:  ] 
# |           33:  Value: 0x1 
# |           34:  } 
# |           35:  Symbol { 
# |            .
# |            .
# |            .
# |           75:  RefType: UndefinedNonLazy (0x0) 
# |           76:  Flags [ (0x0) 
# |           77:  ] 
# |           78:  Value: 0x2 
# |           79:  } 
# |           80: ] 
# | next:26'3       } search range end (exclusive)
# | >>>>>>
# `-----------------------------
# error: command failed with exit status: 1

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/212001