[lldb][Android] Fix platform process list regression (#164333)
## Summary
Fix `FindProcesses` to respect Android's `hidepid=2` security model and
enable name matching for Android apps.
## Problem
1. Called `adb shell pidof` or `adb shell ps` directly, bypassing
Android's process visibility restrictions
2. Name matching failed for Android apps - searched for
`com.example.myapp` but GDB Remote Protocol reports `app_process64`
Android apps fork from Zygote, so `/proc/PID/exe` points to
`app_process64` for all apps. The actual package name is only in
`/proc/PID/cmdline`. The previous implementation applied name filters
without supplementing with cmdline, so searches failed.
## Fix
- Delegate to lldb-server via GDB Remote Protocol (respects `hidepid=2`)
- Get all visible processes, supplement zygote/app_process entries with
cmdline, then apply name matching
- Only fetch cmdline for zygote apps (performance), parallelize with
`xargs -P 8`
- Remove redundant code (GDB Remote Protocol already provides GID/arch)
## Test Results
### Before this fix:
```
(lldb) platform process list
error: no processes were found on the "remote-android" platform
(lldb) platform process list -n com.example.hellojni
1 matching process was found on "remote-android"
PID PARENT USER TRIPLE NAME
====== ====== ========== ============================== ============================
5276 359 u0_a192 com.example.hellojni
^^^^^^^^ Missing triple!
```
### After this fix:
```
(lldb) platform process list
PID PARENT USER TRIPLE NAME
====== ====== ========== ============================== ============================
1 0 root aarch64-unknown-linux-android init
2 0 root [kthreadd]
359 1 system aarch64-unknown-linux-android app_process64
5276 359 u0_a192 aarch64-unknown-linux-android com.example.hellojni
5357 5355 u0_a192 aarch64-unknown-linux-android sh
5377 5370 u0_a192 aarch64-unknown-linux-android lldb-server
^^^^^^^^ User-space processes now have triples!
(lldb) platform process list -n com.example.hellojni
1 matching process was found on "remote-android"
PID PARENT USER TRIPLE NAME
====== ====== ========== ============================== ============================
5276 359 u0_a192 aarch64-unknown-linux-android com.example.hellojni
(lldb) process attach -n com.example.hellojni
Process 5276 stopped
* thread #1, name = 'example.hellojni', stop reason = signal SIGSTOP
```
## Test Plan
With an Android device/emulator connected:
1. Start lldb-server on device:
```bash
adb push lldb-server /data/local/tmp/
adb shell chmod +x /data/local/tmp/lldb-server
adb shell /data/local/tmp/lldb-server platform --listen 127.0.0.1:9500 --server
```
2. Connect from LLDB:
```
(lldb) platform select remote-android
(lldb) platform connect connect://127.0.0.1:9500
(lldb) platform process list
```
3. Verify:
- `platform process list` returns all processes with triple information
- `platform process list -n com.example.app` finds Android apps by
package name
- `process attach -n com.example.app` successfully attaches to Android
apps
## Impact
Restores `platform process list` on Android with architecture
information and package name lookup. All name matching modes now work
correctly.
Fixes https://github.com/llvm/llvm-project/issues/164192