memory: Optimize gum_memory_read for Linux/Android

[DoranekoSystems]

This PR optimizes the performance of gum_memory_read on Linux/Android platforms.

Current Issues:

• gum_memory_read is significantly slow due to parsing memory maps on each call
• Memory.readVolatile using gum_memory_read is approximately 1000x slower than Memory.readByteArray

Improvements:

• Implement process_vm_readv for safe self-process memory reading on Linux kernels >= 3.2
• Add kernel version detection to ensure compatibility

Benchmark results

let memPtr = Memory.alloc(4096);
let start = Date.now();
for(let i = 0; i < 10000; i++) {
  Memory.readVolatile(memPtr, 4096);
}

let end = Date.now();
console.log(`readVolatile => elapsedTime: ${end - start} ms`);
start = Date.now();
for(let i = 0; i < 10000; i++) {
  Memory.readByteArray(memPtr, 4096);
}

end = Date.now();
console.log(`readByteArray => elapsedTime: ${end - start} ms`);

Device:Android Pixel3a

frida-server:16.6.4
readVolatile => elapsedTime: 49432 ms
readByteArray => elapsedTime: 31 ms

this version
readVolatile => elapsedTime: 45 ms
readByteArray => elapsedTime: 31 ms

[oleavr]

Thanks, this is amazing!! 🙌