Auto merge of #78605 - nox:relax-elf-relocations, r=nagisa

Implement -Z relax-elf-relocations=yes|no

This lets rustc users tweak whether the linker should relax ELF relocations without recompiling a whole new target with its own libcore etc.

compiler/rustc_interface/src/tests.rs

@@ -574,6 +574,7 @@ fn test_debugging_options_tracking_hash() {
     tracked!(print_fuel, Some("abc".to_string()));
     tracked!(profile, true);
     tracked!(profile_emit, Some(PathBuf::from("abc")));
+    tracked!(relax_elf_relocations, Some(true));
     tracked!(relro_level, Some(RelroLevel::Full));
     tracked!(report_delayed_bugs, true);
     tracked!(run_dsymutil, false);