Add ctx argument to cc_common.configure_features

In order to migrate C++ rules to platforms, we need the access to the C++
configuration fragment in Starlark APIs. All existing APIs have already access
to it, but cc_common.configure_features doesn't. This change adds a
ctx argument to configure_features.

This is the migration needed for
https://github.com/bazelbuild/bazel/issues/7793, and is part of the effort for
https://github.com/bazelbuild/bazel/issues/6516.

If the rule doesn't depend on cpp fragment yet, you will have to add `fragments
=['cpp']` argument to the rule() call.

Note that this behavior is only available in Bazel 0.25 (to be released this month).

RELNOTES: None.
PiperOrigin-RevId: 247171967

examples/my_c_archive/my_c_archive.bzl

@@ -24,6 +24,7 @@ def _my_c_archive_impl(ctx):
     output_file = ctx.actions.declare_file(ctx.label.name + ".a")
 
     feature_configuration = cc_common.configure_features(
+        ctx = ctx,
         cc_toolchain = cc_toolchain,
         requested_features = ctx.features,
         unsupported_features = ctx.disabled_features,
@@ -90,4 +91,5 @@ my_c_archive = rule(
         "deps": attr.label_list(providers = [CcInfo]),
         "_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
     },
+    fragments = ["cpp"],
 )

examples/my_c_compile/my_c_compile.bzl

@@ -28,6 +28,7 @@ def _my_c_compile_impl(ctx):
     source_file = ctx.file.src
     output_file = ctx.actions.declare_file(ctx.label.name + ".o")
     feature_configuration = cc_common.configure_features(
+        ctx = ctx,
         cc_toolchain = cc_toolchain,
         requested_features = ctx.features,
         unsupported_features = DISABLED_FEATURES + ctx.disabled_features,