[compiler-rt] [win/asan] Add a test skeleton for function GetInstructionSize. (PR #116948)

[via llvm-commits]

bernhardu wrote:

Changes in v3:
- Format the output more like the test line would appear. E.g. before `( 70 71 )`, now `{0x70, 0x71}`.
- Make the comment part of the test data as a string.

Unfortunately, when later adding the longer instruction sequences,
they will still get split to different lines by git-clang-format.

https://github.com/llvm/llvm-project/pull/116948