doc: add mold to speeding up section

PR-URL: #52179
Reviewed-By: Vinícius Lourenço Claro Cardoso <[email protected]>
Reviewed-By: Yagiz Nizipli <[email protected]>

Author: congzhangzh

BUILDING.md

@@ -531,23 +531,30 @@ make test-only
 
 #### Speeding up frequent rebuilds when developing
 
-If you plan to frequently rebuild Node.js, especially if using several branches,
-installing `ccache` can help to greatly reduce build times. Set up with:
+Tips: The `ccache` utility is widely used and should generally work fine.
+If you encounter any difficulties, consider disabling `mold` as a
+troubleshooting step.
+
+If you plan to frequently rebuild Node.js, especially if using several
+branches, installing `ccache` and `mold` can help to greatly reduce build
+times. Set up with:
 
 On GNU/Linux:
 
 ```bash
-sudo apt install ccache   # for Debian/Ubuntu, included in most Linux distros
-export CC="ccache gcc"    # add to your .profile
-export CXX="ccache g++"   # add to your .profile
+sudo apt install ccache mold   # for Debian/Ubuntu, included in most Linux distros
+export CC="ccache gcc"         # add to your .profile
+export CXX="ccache g++"        # add to your .profile
+export LDFLAGS="-fuse-ld=mold" # add to your .profile
 ```
 
 On macOS:
 
 ```bash
-brew install ccache      # see https://brew.sh
-export CC="ccache cc"    # add to ~/.zshrc or other shell config file
-export CXX="ccache c++"  # add to ~/.zshrc or other shell config file
+brew install ccache mold       # see https://brew.sh
+export CC="ccache cc"          # add to ~/.zshrc or other shell config file
+export CXX="ccache c++"        # add to ~/.zshrc or other shell config file
+export LDFLAGS="-fuse-ld=mold" # add to ~/.zshrc or other shell config file
 ```
 
 This will allow for near-instantaneous rebuilds when switching branches back
@@ -565,6 +572,11 @@ the specified directory. The JS debugger of Visual Studio Code supports this
 configuration since the November 2020 version and allows for setting
 breakpoints.
 
+Refs:
+
+1. <https://ccache.dev/performance.html>
+2. <https://github.com/rui314/mold>
+
 #### Troubleshooting Unix and macOS builds
 
 Stale builds can sometimes result in `file not found` errors while building.