Propagate --experimental_cc_implementation_deps to host config

RELNOTES: n/a
PiperOrigin-RevId: 407089786

Author: Googler

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

@@ -1142,6 +1142,7 @@ public FragmentOptions getHost() {
     host.experimentalLinkStaticLibrariesOnce = experimentalLinkStaticLibrariesOnce;
     host.experimentalEnableTargetExportCheck = experimentalEnableTargetExportCheck;
     host.experimentalCcSharedLibraryDebug = experimentalCcSharedLibraryDebug;
+    host.experimentalCcImplementationDeps = experimentalCcImplementationDeps;
 
     host.coptList = coptListBuilder.addAll(hostCoptList).build();
     host.cxxoptList = cxxoptListBuilder.addAll(hostCxxoptList).build();

src/test/java/com/google/devtools/build/lib/rules/cpp/CcLibraryConfiguredTargetTest.java

@@ -1991,6 +1991,37 @@ public void testImplementationDepsLinkingContextIsPropagated() throws Exception
         .contains("bin foo/libimplementation_dep.a");
   }
 
+  @Test
+  public void testImplementationDepsConfigurationHostSucceeds() throws Exception {
+    useConfiguration("--experimental_cc_implementation_deps");
+    scratch.file(
+        "foo/BUILD",
+        "cc_binary(",
+        "    name = 'bin',",
+        "    srcs = ['bin.cc'],",
+        "    deps = ['lib'],",
+        ")",
+        "cc_library(",
+        "    name = 'lib',",
+        "    srcs = ['lib.cc'],",
+        "    deps = ['public_dep'],",
+        ")",
+        "cc_library(",
+        "    name = 'public_dep',",
+        "    srcs = ['public_dep.cc'],",
+        "    hdrs = ['public_dep.h'],",
+        "    implementation_deps = ['implementation_dep'],",
+        ")",
+        "cc_library(",
+        "    name = 'implementation_dep',",
+        "    srcs = ['implementation_dep.cc'],",
+        "    hdrs = ['implementation_dep.h'],",
+        ")");
+
+    getHostConfiguredTarget("//foo:bin");
+    assertDoesNotContainEvent("requires --experimental_cc_implementation_deps");
+  }
+
   @Test
   public void testImplementationDepsFailsWithoutFlag() throws Exception {
     scratch.file(