Extremely long link time

Running on version 3.1.60

We have a quite large repository that we build using Emscripten. The link time became quite time-consuming (~2min on Intel i7 12700F), which is unusually long since lld (and its port wasm-ld) should be very fast and typically not the bottleneck in the build process.

We went through the following issue https://github.com/emscripten-core/emscripten/issues/17019 and applied both flags `-sERROR_ON_WASM_CHANGES_AFTER_LINK -sWASM_BIGINT`. We build/link with `-Og`.

This is the `EMPROFILE=2` verbose output for the final link stage:
```
...
profiler:INFO: start block "link"
profiler:INFO: block "link" took 147.589 seconds
profiler:INFO: start block "post link"
profiler:INFO: start block "emscript"
profiler:INFO: start block "get_metadata"
profiler:INFO: block "get_metadata" took 1.040 seconds
profiler:INFO: start block "compile_javascript"
profiler:INFO: block "compile_javascript" took 0.208 seconds
profiler:INFO: block "emscript" took 3.278 seconds
profiler:INFO: start block "binaryen"
profiler:INFO: start block "use_unsigned_pointers_in_js"
profiler:INFO: block "use_unsigned_pointers_in_js" took 0.598 seconds
profiler:INFO: start block "apply_wasm_memory_growth"
profiler:INFO: block "apply_wasm_memory_growth" took 1.007 seconds
profiler:INFO: block "binaryen" took 3.300 seconds
profiler:INFO: start block "final emitting"
profiler:INFO: block "final emitting" took 1.497 seconds
profiler:INFO: block "post link" took 8.077 seconds
profiler:INFO: block "main" took 155.752 seconds
```

These are our build flags:
```
FLAGS = -stdlib=libc++ -pthread -sSHARED_MEMORY=1 -sUSE_PTHREADS=1 LINK_FLAGS = -pthread -sSHARED_MEMORY=1 -sUSE_PTHREADS=1 -sMALLOC=mimalloc "-S --allow-multiple-definition" --closure 1 --closure-args=--jscomp_off=* -sLEGACY_GL_EMULATION -sGL_UNSAFE_OPTS=0 -sGL_FFP_ONLY=1 -WASM=1 --bind -sDISABLE_DEPRECATED_FIND_EVENT_TARGET_BEHAVIOR=1 -sMODULARIZE=1 -sFORCE_FILESYSTEM=1 -sEXPORT_NAME=createModuleFactory -sALLOW_MEMORY_GROWTH=1 -sMALLOC=mimalloc -sINITIAL_MEMORY=1GB -sMAXIMUM_MEMORY=4GB -sPROXY_TO_PTHREAD -sEXIT_RUNTIME=1 -sALLOW_BLOCKING_ON_MAIN_THREAD=1 "-sEXPORTED_RUNTIME_METHODS=['FS','PATH','ERRNO_CODES']" "-sPTHREAD_POOL_SIZE='navigator.hardwareConcurrency*2+1'" -error-limit=0 -sASSERTIONS=1 -sNO_DISABLE_EXCEPTION_CATCHING -gseparate-dwarf -Og --profiling-funcs -sREVERSE_DEPS=all -sWASM_BIGINT -sERROR_ON_WASM_CHANGES_AFTER_LINK
```

Is there anything that you suggest can be done in order to decrease the link time?