Replace CppSemantics mechanism with semantics.bzl.

The proper values for toolchain type and include validation are passed through to CppCompileActionBuilder from semantics.bzl

This change removes `getCppToolchainType`, `language`, and `needsIncludeValidation` from the `CppSemantics` interface and its implementations. There's no need to pass through `CppSemantics` in `compile.bzl` anymore.

The change could be further simplified by setting needsIncludeValidation always to true.

PiperOrigin-RevId: 820281232
Change-Id: Ia51992e836a68a91d7387722fe170d53a1285ee2

Author: comius

cc/common/semantics.bzl

@@ -155,6 +155,9 @@ def _validate_cc_compile_call(
         fail("The 'additional_include_scanning_roots' parameter doesn't do anything useful. " +
              "This is only used internally for a mechanism we'd like to get rid of.")
 
+def _needs_include_validation(language):
+    return language == "c++" or language == "cpp" or language == None
+
 semantics = struct(
     toolchain = "@bazel_tools//tools/cpp:toolchain_type",
     validate = _validate,
@@ -199,6 +202,7 @@ semantics = struct(
     CC_PROTO_TOOLCHAIN = "@rules_cc//cc/proto:toolchain_type",
     is_bazel = True,
     validate_cc_compile_call = _validate_cc_compile_call,
+    needs_include_validation = _needs_include_validation,
     extra_exec_groups = {},
     stamp_extra_docs = "",
     malloc_docs = """