Use find_cpp_toolchain in compile_commands.bzl (#2845)
Use find_cpp_toolchain in compile_commands.bzl (#2845)

Migrate CToolchain-dependent ctx.fragments.cpp field calls to receive the information from toolchains. This is an intermediate step in migrating to the new Skylark API for the C++ toolchain. The extra _cc_toolchain attribute will be removed later in this migration.
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