Don't rely on hardcoded file extensions.

idea/src/org/jetbrains/jet/plugin/compiler/WholeProjectAnalyzerFacade.java

@@ -3,6 +3,8 @@ package org.jetbrains.jet.plugin.compiler;
 import com.google.common.collect.Sets;
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.compiler.ex.CompilerPathsEx;
+import com.intellij.openapi.fileTypes.FileType;
+import com.intellij.openapi.fileTypes.FileTypeManager;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.roots.ProjectRootManager;
 import com.intellij.openapi.vfs.VirtualFile;
@@ -14,6 +16,7 @@ import org.jetbrains.jet.lang.psi.JetDeclaration;
 import org.jetbrains.jet.lang.psi.JetFile;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.java.AnalyzerFacade;
+import org.jetbrains.jet.plugin.JetFileType;
 
 import java.util.Collection;
 import java.util.Set;
@@ -34,7 +37,8 @@ public class WholeProjectAnalyzerFacade {
                 CompilerPathsEx.visitFiles(contentRoots, new CompilerPathsEx.FileVisitor() {
                     @Override
                     protected void acceptFile(VirtualFile file, String fileRoot, String filePath) {
-                        if (!(file.getName().endsWith(".kt") || file.getName().endsWith(".kts"))) return;
+                        final FileType fileType = FileTypeManager.getInstance().getFileTypeByFile(file);
+                        if (fileType != JetFileType.INSTANCE) return;
                         PsiFile psiFile = PsiManager.getInstance(project).findFile(file);
                         if (psiFile instanceof JetFile) {
                             namespaces.add(((JetFile) psiFile).getRootNamespace());