support per version visibility

Summary:
The `visibility` config within `fixups.toml` is only supported as a top level config or within `export_sources` so if one wants to modify visibility per crate version, there is currently no way to do that. I considered a couple of design approaches moving forward including making `version` a 1st class citizen by supporting `version` tables:

```toml
[version."=2.2.1"]
overlay = "some_overlay"
visibility = ["//some/..."],

[version."<2.2.1"]
overlay = "other_overlay"
visibility = ["//other/..."],
```
but the above needs a larger redesign we would have to move `version` out of per-platform configs. Since we are to move to a `fixups.bzl` implementation, I'd rather spent the time then and design the `fixups.bzl` spec from the ground up. For now, I went with the least intrusive approach by allowing the top level `visibility` to accept both TOML array and table values. Array values is what is currently supported:

```toml
visibility = ["//some/..."]
```

and table values looks like so:

```
[visibility]
"=2.2.1" = ["//some/..."]
">2.2.1" = ["//other/..."]
```

Reviewed By: dtolnay

Differential Revision: D74600208

fbshipit-source-id: 5265517c87d16d1b7d17c18387b0bbed12531f5f

Author: diliop

src/fixups.rs

@@ -45,6 +45,7 @@ use crate::cargo::TargetKind;
 use crate::collection::SetOrMap;
 use crate::config::Config;
 use crate::config::VendorConfig;
+use crate::fixups::config::CustomVisibility;
 use crate::glob::Globs;
 use crate::glob::NO_EXCLUDE;
 use crate::glob::SerializableGlobSet as GlobSet;
@@ -188,8 +189,16 @@ impl<'meta> Fixups<'meta> {
     }
 
     pub fn public_visibility(&self) -> Visibility {
-        match self.fixup_config.custom_visibility.as_deref() {
-            Some(visibility) => Visibility::Custom(visibility.to_vec()),
+        match self.fixup_config.custom_visibility.as_ref() {
+            Some(visibility) => match visibility {
+                CustomVisibility::NoVersion(global) => Visibility::Custom(global.to_vec()),
+                CustomVisibility::WithVersion(versioned) => versioned
+                    .iter()
+                    .filter(|(k, _)| k.matches(&self.package.version))
+                    .map(|(_, v)| Visibility::Custom(v.to_vec()))
+                    .next()
+                    .unwrap_or(Visibility::Public),
+            },
             None => Visibility::Public,
         }
     }

src/fixups/config.rs

@@ -7,6 +7,7 @@
 
 use std::collections::BTreeMap;
 use std::collections::BTreeSet;
+use std::collections::HashMap;
 use std::collections::HashSet;
 use std::fmt;
 use std::path::Path;
@@ -36,7 +37,7 @@ pub struct FixupConfigFile {
     /// This only has an effect for top-level crates. Exposed crates
     /// by default get `visibility = ["PUBLIC"]`. Sometimes you want to
     /// discourage use of some crate by limiting its visibility.
-    pub custom_visibility: Option<Vec<String>>,
+    pub custom_visibility: Option<CustomVisibility>,
 
     /// Omit a target
     pub omit_targets: BTreeSet<String>,
@@ -314,6 +315,13 @@ impl<'de> Deserialize<'de> for CargoEnvs {
     }
 }
 
+#[derive(Debug, Deserialize)]
+#[serde(untagged)]
+pub enum CustomVisibility {
+    NoVersion(Vec<String>),
+    WithVersion(HashMap<semver::VersionReq, Vec<String>>),
+}
+
 struct FixupConfigFileVisitor;
 
 impl<'de> Visitor<'de> for FixupConfigFileVisitor {

test/common/simple-two/Cargo.toml

@@ -0,0 +1,4 @@
+[package]
+name = "simple"
+version = "0.1.0"
+publish = false

test/common/simple-two/src/lib.rs

@@ -0,0 +1,10 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+pub fn simple() {
+    println!("I am a simple crate")
+}