Remove copied core modules from ruff_python_formatter (#3371)

crates/ruff_python_formatter/src/context.rs

@@ -1,15 +1,21 @@
-use ruff_formatter::{FormatContext, SimpleFormatOptions};
+use std::rc::Rc;
 
-use crate::core::locator::Locator;
+use ruff_formatter::{FormatContext, SimpleFormatOptions};
+use ruff_python_ast::source_code::Locator;
 
 pub struct ASTFormatContext<'a> {
     options: SimpleFormatOptions,
+    contents: Rc<str>,
     locator: Locator<'a>,
 }
 
 impl<'a> ASTFormatContext<'a> {
     pub fn new(options: SimpleFormatOptions, locator: Locator<'a>) -> Self {
-        Self { options, locator }
+        Self {
+            options,
+            contents: Rc::from(locator.contents()),
+            locator,
+        }
     }
 }
 
@@ -22,6 +28,10 @@ impl FormatContext for ASTFormatContext<'_> {
 }
 
 impl<'a> ASTFormatContext<'a> {
+    pub fn contents(&'a self) -> Rc<str> {
+        self.contents.clone()
+    }
+
     pub fn locator(&'a self) -> &'a Locator {
         &self.locator
     }