Automated rollback of commit 2b983bdf508e010a3d4ee9dbaf446b7666749799.

*** Reason for rollback ***

Breaks rules_go CI

*** Original change description ***

Rollforward of c++ toolchain-relevant BUILD file and Bazel mocking changes.  That is, a c++ toolchain is added, but a Bazel dependency on that toolchain is not.

PiperOrigin-RevId: 167198874
diff --git a/src/create_embedded_tools.py b/src/create_embedded_tools.py
index 668db21..699edd0 100644
--- a/src/create_embedded_tools.py
+++ b/src/create_embedded_tools.py
@@ -29,8 +29,8 @@
 
 output_paths = [
     ('*tools/jdk/BUILD*', lambda x: 'tools/jdk/BUILD'),
-    ('*tools/platforms/platforms.BUILD', lambda x: 'tools/platforms/BUILD'),
-    ('*tools/platforms/*', lambda x: 'tools/platforms/' + os.path.basename(x)),
+    ('*tools/platforms/platforms.BUILD', lambda x: 'platforms/BUILD'),
+    ('*tools/platforms/*', lambda x: 'platforms/' + os.path.basename(x)),
     ('*JavaBuilder*_deploy.jar', lambda x: 'tools/jdk/' + os.path.basename(x)),
     ('*JacocoCoverage*_deploy.jar',
      lambda x: 'tools/jdk/JacocoCoverage_deploy.jar'),