feat(allocator): add From API (#1908)

closes #1701

crates/oxc_allocator/src/lib.rs

@@ -1,4 +1,4 @@
-use std::ops::Deref;
+use std::{convert::From, ops::Deref};
 
 mod arena;
 
@@ -10,6 +10,12 @@ pub struct Allocator {
     bump: Bump,
 }
 
+impl From<Bump> for Allocator {
+    fn from(bump: Bump) -> Self {
+        Self { bump }
+    }
+}
+
 impl Deref for Allocator {
     type Target = Bump;
 
@@ -17,3 +23,21 @@ impl Deref for Allocator {
         &self.bump
     }
 }
+
+#[cfg(test)]
+mod test {
+    use std::ops::Deref;
+
+    use crate::Allocator;
+    use bumpalo::Bump;
+
+    #[test]
+    fn test_api() {
+        let bump = Bump::new();
+        let allocator: Allocator = bump.into();
+        #[allow(clippy::explicit_deref_methods)]
+        {
+            _ = allocator.deref();
+        }
+    }
+}