message: Just don't even attempt to invoke sed on Windows.
diff: @@ -253,7 +253,12 @@ ifeq "$(MAKE_DWO)" "YES"
  endif
  # Use a shared module cache when building in the default test build directory.
  +ifeq "$(OS)" "Windows_NT"
  +CLANG_MODULE_CACHE_DIR := $(BUILDDIR)/module-cache
  +else
  +# FIXME: Get sed to work on Windows here.
  CLANG_MODULE_CACHE_DIR := $(shell echo "$(BUILDDIR)" | sed 's/lldb-test-build.noindex.*/lldb-test-build.noindex\/module-cache-clang/')
  +endif
  ifeq "$(findstring lldb-test-build.noindex, $(BUILDDIR))" ""
  CLANG_MODULE_CACHE_DIR := $(BUILDDIR)/module-cache
  