[clang] [Clang][Cmake] fix libtool duplicate member name warnings (PR #133619)

[Farzon Lotfi via cfe-commits]

farzonl wrote:

@nikic  what is considered a neglible difference in elapsesed time? Elapsed is consistently a little more after my change in the order of 5-20 seconds. Examples below:

## Specs
```
processor       : 63
vendor_id       : AuthenticAMD
cpu family      : 25
model           : 8
model name      : AMD Ryzen Threadripper PRO 5975WX 32-Cores
stepping        : 2
microcode       : 0xa008205
cpu MHz         : 1800.000
cache size      : 512 KB
physical id     : 0
siblings        : 64
core id         : 31
cpu cores       : 32
```

## Debug build before changes:
```
[5363/5363] Generated
        Command being timed: "ninja -C ../llvm_debug_build/"
        User time (seconds): 28679.90
        System time (seconds): 1482.99
        Percent of CPU this job got: 5620%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 8:56.62
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 10034904
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 89825
        Minor (reclaiming a frame) page faults: 310462049
        Voluntary context switches: 1261232
        Involuntary context switches: 1125893
        Swaps: 0
        File system inputs: 37896
        File system outputs: 112778048
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 0
```
## Release build before changes:
```
ninja: Entering directory `../llvm_release_build/'
[5363/5363] Generated
        Command being timed: "ninja -C ../llvm_release_build/"
        User time (seconds): 25730.83
        System time (seconds): 1238.55
        Percent of CPU this job got: 6140%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 7:19.22
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 1696776
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 2113
        Minor (reclaiming a frame) page faults: 268141745
        Voluntary context switches: 551323
        Involuntary context switches: 1124237
        Swaps: 0
        File system inputs: 944
        File system outputs: 10928088
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 0
```
## Release build after changes:
```
 [5365/5365] Generated
        Command being timed: "ninja -C ../llvm_release_build/"
        User time (seconds): 25542.24
        System time (seconds): 1235.53
        Percent of CPU this job got: 5852%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 7:37.54
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 1695512
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 2075
        Minor (reclaiming a frame) page faults: 268176633
        Voluntary context switches: 554573
        Involuntary context switches: 1113659
        Swaps: 0
        File system inputs: 264
        File system outputs: 11055600
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 0
```
## Debug build after changes:
```
[5365/5365] Generated
        Command being timed: "ninja -C ../llvm_debug_build/"
        User time (seconds): 28477.94
        System time (seconds): 1469.80
        Percent of CPU this job got: 5523%
        Elapsed (wall clock) time (h:mm:ss or m:ss): 9:02.20
        Average shared text size (kbytes): 0
        Average unshared data size (kbytes): 0
        Average stack size (kbytes): 0
        Average total size (kbytes): 0
        Maximum resident set size (kbytes): 10817400
        Average resident set size (kbytes): 0
        Major (requiring I/O) page faults: 89172
        Minor (reclaiming a frame) page faults: 310414009
        Voluntary context switches: 1002199
        Involuntary context switches: 1243091
        Swaps: 0
        File system inputs: 384
        File system outputs: 112886080
        Socket messages sent: 0
        Socket messages received: 0
        Signals delivered: 0
        Page size (bytes): 4096
        Exit status: 0
```

https://github.com/llvm/llvm-project/pull/133619