Prevent crash when using a tree artifact in cc_library's srcs

The check to determine which subset of the toolchain files to provide
as inputs requires knowing the file type. actionBuilder::getActionName()
throws IllegalStateException when given a tree artifact (directory).

In this case, we provide all toolchain files as inputs, since Bazel does
not know the content of the directory at this time.

PiperOrigin-RevId: 339271792

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

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/cpp/BazelCppSemantics.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/cpp/BazelCppSemantics.java
index f8b70cf..630e128 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/cpp/BazelCppSemantics.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/cpp/BazelCppSemantics.java
@@ -68,6 +68,7 @@
     actionBuilder
         .addTransitiveMandatoryInputs(
             configuration.getFragment(CppConfiguration.class).useSpecificToolFiles()
+                    && !actionBuilder.getSourceFile().isTreeArtifact()
                 ? (actionBuilder.getActionName().equals(CppActionNames.ASSEMBLE)
                     ? toolchain.getAsFiles()
                     : toolchain.getCompilerFiles())