[clang][Driver] Fix enabling strict alising by default when the environment is MSVC (#91689)
From looking at the rest of code and from my own understanding, the
driver mode is supposed to be independent of MSVC compatibility when the
target triple is `*-windows-msvc`.
Therefore strict aliasing should be disabled by default when the target
triple is `*-windows-msvc` so code assuming MSVC behaves as expected
when compiled with Clang.