Set gcc warning flags via --host_cxxopt as well

Signed-off-by: Michael Warres <[email protected]>

Author: mpwarres

.bazelrc

@@ -65,8 +65,8 @@ build:clang-tidy --output_groups=report
 build:gcc --action_env=BAZEL_COMPILER=gcc
 build:gcc --action_env=CC=gcc
 build:gcc --action_env=CXX=g++
-build:gcc --cxxopt -Wno-invalid-offsetof
-build:gcc --cxxopt -Wno-deprecated
+build:gcc --cxxopt -Wno-invalid-offsetof --host_cxxopt -Wno-invalid-offsetof
+build:gcc --cxxopt -Wno-deprecated --host_cxxopt -Wno-deprecated
 
 # Use Zig C/C++ compiler.
 build:zig-cc --incompatible_enable_cc_toolchain_resolution