JS backend: don't add file:// prefix to sourcemap url.

Use name of generated source map file instead of absolute path.

(cherry picked from commit 126e977 and ec2fc20)

js/js.translator/src/org/jetbrains/js/compiler/sourcemap/SourceMap3Builder.java

@@ -131,8 +131,9 @@ public class SourceMap3Builder implements SourceMapBuilder {
 
     @Override
     public void addLink() {
-        textOutput.print("\n//@ sourceMappingURL=file://");
-        textOutput.print(getOutFile().getAbsolutePath());
+        textOutput.print("\n//@ sourceMappingURL=");
+        textOutput.print(generatedFile.getName());
+        textOutput.print(".map");
     }
 
     private static final class Base64VLQ {
@@ -146,6 +147,7 @@ public class SourceMap3Builder implements SourceMapBuilder {
         // The continuation bit is the 6th bit.
         private static final int VLQ_CONTINUATION_BIT = VLQ_BASE;
 
+        @SuppressWarnings("SpellCheckingInspection")
         private static final char[] BASE64_MAP = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
 
         private Base64VLQ() {