[Fix]: Add RIP-relative addressing across all memory accesses

[douxxtech]

Every direct memory reference ([label]) has been replaced with its RIP-relative form ([rel label]). This is a position-independent code (PIC) fix, without rel, the assembler generates absolute addressing which breaks when the binary isn't loaded at a fixed address (e.g. with ASLR enabled, or when linked as a shared/PIE executable).

Side note: I'm not sure if this broke things or not. The tests seem to pass just fine though. And it's fine anyways, its an experimental project.

[github-actions]

START + GET /: 166 syscalls
Fastest: 0.000017s (brk)
Slowest: 0.817329s (accept)

threads: 4 (auto), conns: 50, duration: 20s

[wrk]
Running 20s test @ http://127.0.0.1:8080/
  4 threads and 50 connections
  Thread Stats   Avg      Stdev     Max   +/- Stdev
    Latency     5.47ms   11.88ms 420.74ms   99.33%
    Req/Sec     1.60k   312.97     2.41k    68.38%
  127216 requests in 20.04s, 193.02MB read
  Socket errors: connect 0, read 35, write 0, timeout 0
Requests/sec:   6349.46
Transfer/sec:      9.63MB