Internal Windows builds will catch issues that we cannot yet catch in
OSS. This will be mostly remedied once we have clang-cl in our CI (See a
rough roadmap in https://github.com/grpc/grpc/pull/32448). For now, this
PR identifies folders where most Windows-specific code is developed, and
requires cherrypicks for PRs that touch anything inside those folders.
This PR also refactors gpr and gprpp source files to better isolate all
platform-specific code ~the Windows-only code~. ~I will reorganize the
other platform-specific files using this structure if there are no
objections.~
This subset of folders covers about half of the `#ifdef GPR_WINDOWS`
usages in gRPC, but nearly all of the actively-developed Windows code
locations.
AJ Heller