remove unnecessary sourcemap encode

src/compiler/preprocess/index.ts

@@ -177,7 +177,7 @@ export default async function preprocess(
 			}
 		);
 		source = res.string;
-		sourcemap_list.unshift(res.get_sourcemap());
+		sourcemap_list.unshift(res.map);
 	}
 
 	for (const fn of style) {
@@ -210,7 +210,7 @@ export default async function preprocess(
 			}
 		);
 		source = res.string;
-		sourcemap_list.unshift(res.get_sourcemap());
+		sourcemap_list.unshift(res.map);
 	}
 
 	// https://github.com/ampproject/remapping#usage

src/compiler/utils/string_with_sourcemap.ts

@@ -1,5 +1,3 @@
-import { encode as sourcemap_encode } from "sourcemap-codec";
-
 type MappingSegment =
 	| [number]
 	| [number, number, number, number]
@@ -65,15 +63,6 @@ export class StringWithSourcemap {
 		this.map = map;
 	}
 
-	get_sourcemap() {
-		return {
-			version: 3,
-			sources: this.map.sources.slice(),
-			names: this.map.names.slice(),
-			mappings: sourcemap_encode(this.map.mappings as any)
-		};
-	}
-
 	concat(other: StringWithSourcemap): StringWithSourcemap {
 		// noop: if one is empty, return the other
 		if (this.string == '') return other;