100% CPU usage when there's a symlink to a different disk drive on Linux

I am experiencing this exact same issue.
What I have also noticed is that when I run htop, I see a single thread of the C/C++ extension constantly at 100% cpu usage. This happens anytime I compile the code and lasts until I close VSCode.

SW Versions:

• Manjaro 5.10.7
• VSCode 1.54.3
• C/C++ 1.2.2

The output window only has a single 'instance' for the C/C++ extension: "C/C++ Configuration Warnings". In this window it seems to be switching between IntelliSense modes willy-nilly. A small excerpt of the logs (in reality it is quite lengthy, but a lot of them are duplicate entries):

[3/23/2021, 3:06:10 PM] For C source files, IntelliSenseMode was changed from "linux-clang-x64" to "linux-gcc-x64" based on compiler args and querying compilerPath: "/usr/bin/gcc"
[3/23/2021, 3:06:10 PM] For C++ source files, IntelliSenseMode was changed from "linux-clang-x64" to "linux-gcc-x64" based on compiler args and querying compilerPath: "/usr/bin/gcc"
[3/23/2021, 3:06:14 PM] For C source files, IntelliSenseMode was changed from "linux-clang-x64" to "linux-gcc-arm" based on compiler args and querying compilerPath: "/usr/bin/arm-none-eabi-gcc"
[3/23/2021, 3:06:14 PM] For C++ source files, IntelliSenseMode was changed from "linux-clang-x64" to "linux-gcc-x64" based on compiler args and querying compilerPath: "/usr/bin/gcc"

If I manually specify for it to use any of these compilerPaths, it will warn about changing to clang (effectively printing the same, but reversed). This doesn't fix the issue however.

Originally posted by @dimitry-boersma in https://github.com/microsoft/vscode-cpptools/issues/7197#issuecomment-804973395

Start by reproducing the Linux case with a symlink to another disk, compiling the project while watching htop and the C/C++ Configuration Warnings output. Trace the repeated IntelliSenseMode changes involving compilerPath values such as /usr/bin/gcc and /usr/bin/arm-none-eabi-gcc. Done means the mode no longer oscillates and the extension thread does not remain at 100% CPU after compilation.