for enabling/disabling v2 control flow.
*   Enable v2 control flow as part of `tf.enable_v2_behavior()` and
    `TF2_BEHAVIOR=1`.
*   AutoGraph translates Python control flow into TensorFlow expressions,
    allowing users to write regular Python inside `tf.function`-decorated
    functions. AutoGraph is also applied in functions used with `tf.data`,
    `tf.distribute` and `tf.keras` APIS.

pkg reflect, method (Value) Grow(int) #48000
pkg reflect, method (Value) SetZero() #52376
pkg regexp/syntax, const ErrLarge ErrorCode #56041
pkg regexp/syntax, const ErrLarge = "expression too large" #56041
pkg runtime/cgo (darwin-amd64-cgo), type Incomplete struct #46731
pkg runtime/cgo (darwin-arm64-cgo), type Incomplete struct #46731
pkg runtime/cgo (freebsd-386-cgo), type Incomplete struct #46731