more bazelrc ubsan tweaks

Author: scotthart

.bazelrc

@@ -20,6 +20,9 @@ build --enable_platform_specific_config=true
 
 build --features=external_include_paths
 
+build --per_file_copt=grpc+//@-Wprivate
+
+
 # The project requires C++ >= 17.
 build:linux --cxxopt=-std=c++17
 build:macos --cxxopt=-std=c++17
@@ -108,6 +111,8 @@ build:ubsan --copt=-DCURL_STRICTER
 build:ubsan --linkopt=-fsanitize=undefined
 build:ubsan --linkopt=-fsanitize-link-c++-runtime
 build:ubsan --action_env=UBSAN_OPTIONS=halt_on_error=1:print_stacktrace=1
+build:ubsan --features=external_include_paths
+
 
 # --config xsan: Runs misc. sanitizers that aren't covered elsewhere.
 build:xsan --config=sanitizer