Add a new toolchain type for c++. In order to do this, PlatformConfiguration is made a legal configuration fragment for every rule class.
Add a default "dummy" c++ toolchain to prevent resolution errors when legacy toolchain selection logic is used. Add toolchain mocks to java and shell tests.
PiperOrigin-RevId: 167901210
diff --git a/compile.sh b/compile.sh
index dc414b1..c72a802 100755
--- a/compile.sh
+++ b/compile.sh
@@ -81,7 +81,11 @@
new_step 'Building Bazel with Bazel'
display "."
log "Building output/bazel"
+# We set host and target platform directly since the defaults in @bazel_tools
+# have not yet been generated.
bazel_build "src:bazel${EXE_EXT}" \
+ --experimental_host_platform=//tools/platforms:host_platform \
+ --experimental_platforms=//tools/platforms:target_platform \
|| fail "Could not build Bazel"
bazel_bin_path="$(get_bazel_bin_path)/src/bazel${EXE_EXT}"
[ -e "$bazel_bin_path" ] \
