Add support for arm and arm64 intelliSenseModes

[sean-mcmanus]

This is semi-separate from the other issues tracking our extension running on ARM machines, i.e. this is for whenever the user's code is built to target arm.

intelliSenseModes would be gcc-arm, gcc-arm64, clang-arm, clang-arm64, windows-arm, windows-arm64 .

Originally reported at #4269 .

[EmbeddedBacon]

When use VS Code and the remote extension to edit on a Raspberry Pi (v3 in this case) I see the error:

Architecture arm is not supported.
Source: C/C++ (Extension)

This is the issue tracking this feature, correct?

[sean-mcmanus]

Running on ARM is being tracked by #429 and #2506. This issue is related, but would repro even on a non-ARM machine that was targeting ARM.

[EmbeddedBacon]

@thanks, Mr. @sean-mcmanus . I will make sure to watch these two other threads. Thanks!

[boardkeystown]

It would be super helpful if there was some way to use intelliSenseModes for the raspberry pi 2,3,and 4.