Support relative paths in settings.json/c_cpp_properties.json without using ${workspaceFolder}

[sean-mcmanus]

Currently, most settings require using ${workspaceFolder} to use relative paths...we could simplify the experience by using implicit relative paths. +1 this if anyone particularly wants this.

[m417z]

I'm interested in having the ability to use a relative path for compilerPath. Specifically, a path relative to the VSCode installation.
One use case: A portable package of VSCode and a compiler.

Say I have a disk-on-key with:

D:\
    vscode\
        Code.exe
        [...]
    gcc\
        bin\
            g++.exe
            [...]
        [...]

I'd like to be able to use:
"C_Cpp.default.compilerPath": "..\\gcc\\bin\\g++.exe"
or:
"C_Cpp.default.compilerPath": "${execPath}\\..\\gcc\\bin\\g++.exe"

If there's a way to do that with the current extension, please tell me how to do that, thanks.

[bobbrow]

This was implemented a while ago, not exactly sure when.