Pass overwrittenVariables to C++ compile action args

With this CL aspects have access to C++ modules specific compiler flags.

RELNOTES: None.
PiperOrigin-RevId: 283708758

src/main/java/com/google/devtools/build/lib/rules/cpp/CompileCommandLine.java

@@ -106,14 +106,17 @@ protected List<String> getArguments(
 
   /**
    * Returns {@link CommandLine} instance that contains the exactly same command line as the {@link
-   * CppCompileAction} owning this {@link CompileCommandLine}.
+   * CppCompileAction}.
+   *
+   * @param cppCompileAction - {@link CppCompileAction} owning this {@link CompileCommandLine}.
    */
-  public CommandLine getFilteredFeatureConfigurationCommandLine() {
+  public CommandLine getFilteredFeatureConfigurationCommandLine(CppCompileAction cppCompileAction) {
     return new CommandLine() {
 
       @Override
       public Iterable<String> arguments() throws CommandLineExpansionException {
-        return ImmutableList.copyOf(getCompilerOptions(/* overwrittenVariables= */ null));
+        CcToolchainVariables overwrittenVariables = cppCompileAction.getOverwrittenVariables();
+        return ImmutableList.copyOf(getCompilerOptions(overwrittenVariables));
       }
     };
   }

src/main/java/com/google/devtools/build/lib/rules/cpp/CppCompileAction.java

@@ -854,7 +854,7 @@ public Sequence<CommandLineArgsApi> getStarlarkArgs() throws EvalException {
             .filter(artifact -> artifact.isDirectory())
             .collect(ImmutableSet.toImmutableSet());
 
-    CommandLine commandLine = compileCommandLine.getFilteredFeatureConfigurationCommandLine();
+    CommandLine commandLine = compileCommandLine.getFilteredFeatureConfigurationCommandLine(this);
 
     CommandLineAndParamFileInfo commandLineAndParamFileInfo =
         new CommandLineAndParamFileInfo(commandLine, /* paramFileInfo= */ null);
@@ -1169,6 +1169,10 @@ private static CcToolchainVariables getOverwrittenVariables(Iterable<Artifact> p
     return variableBuilder.build();
   }
 
+  public CcToolchainVariables getOverwrittenVariables() {
+    return overwrittenVariables;
+  }
+
   @Override
   public Iterable<Artifact> getAllowedDerivedInputs() {
     Set<Artifact> result = CompactHashSet.create();