Remove uses of rules_cc (#776)

Per https://github.com/bazelbuild/rules_cc this still isn't necessary. There's no build-time enforcement, so usage is inconsistent/incorrect. Rather than letting this linger, remove it pending Bazel tooling enforcing it.

executable_semantics/BUILD

@@ -2,7 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library")
 load("//bazel/testing:golden_test.bzl", "golden_test")
 load("test_list.bzl", "TEST_LIST")
 

executable_semantics/ast/BUILD

@@ -2,8 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library")
-
 package(default_visibility = ["//executable_semantics:__subpackages__"])
 
 cc_library(

executable_semantics/interpreter/BUILD

@@ -2,8 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library")
-
 package(default_visibility = ["//executable_semantics:__subpackages__"])
 
 cc_library(

executable_semantics/syntax/BUILD

@@ -2,8 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library")
-
 package(default_visibility = ["//executable_semantics:__pkg__"])
 
 cc_library(

migrate_cpp/cpp_refactoring/BUILD

@@ -2,8 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library", "cc_test")
-
 package(default_visibility = ["//visibility:public"])
 
 cc_binary(

third_party/examples/woff2/BUILD.original

@@ -4,8 +4,6 @@
 
 # Rules are adapted from CMakeLists.txt.
 
-load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
-
 package(
     default_visibility = ["//visibility:public"],
 )

third_party/examples/woff2/carbon/BUILD

@@ -4,8 +4,6 @@
 
 # Rules are adapted from CMakeLists.txt.
 
-load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
-
 package(
     default_visibility = ["//visibility:public"],
 )

toolchain/common/BUILD

@@ -2,8 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
-
 package(default_visibility = ["//visibility:public"])
 
 cc_library(

toolchain/diagnostics/BUILD

@@ -2,8 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
-
 package(default_visibility = ["//visibility:public"])
 
 cc_library(

toolchain/driver/BUILD

@@ -2,7 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_binary", "cc_library", "cc_test")
 load("//bazel/fuzzing:rules.bzl", "cc_fuzz_test")
 
 package(default_visibility = ["//visibility:public"])

toolchain/lexer/BUILD

@@ -2,7 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 load("//bazel/fuzzing:rules.bzl", "cc_fuzz_test")
 
 package(default_visibility = ["//visibility:public"])

toolchain/parser/BUILD

@@ -2,7 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 load("//bazel/fuzzing:rules.bzl", "cc_fuzz_test")
 
 package(default_visibility = ["//visibility:public"])

toolchain/source/BUILD

@@ -2,8 +2,6 @@
 # Exceptions. See /LICENSE for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
-
 package(default_visibility = ["//visibility:public"])
 
 cc_library(