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

[via llvm-commits]

bernhardu wrote:

Changes in v2:
- Really left just SIZE_T in the header.
- s/unsigned int/unsigned/
- s/InstructionSizeData_t/InstructionSizeData/
- s/byteIndex/i/
- s/arrayIndex/i/
- checked commit with `git-clang-format --diff 47ef5c4b7f85`


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