better location diagnostic of internal errors

compiler/backend/src/org/jetbrains/jet/codegen/ClassBodyCodegen.java

@@ -73,6 +73,9 @@ public abstract class ClassBodyCodegen {
         else if (declaration instanceof JetNamedFunction) {
             try {
                 genNamedFunction((JetNamedFunction) declaration, functionCodegen);
+            }
+            catch(CompilationException e) {
+                throw e;
             } catch (RuntimeException e) {
                 throw new RuntimeException("Error generating method " + myClass.getName() + "." + declaration.getName() + " in " + context, e);
             }

compiler/backend/src/org/jetbrains/jet/codegen/CompilationException.java

@@ -1,7 +1,15 @@
 package org.jetbrains.jet.codegen;
 
+import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.util.TextRange;
+import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiElement;
+import com.intellij.psi.PsiFile;
 import org.jetbrains.jet.lang.psi.JetElement;
+import org.jetbrains.jet.resolve.DescriptorRenderer;
+import org.objectweb.asm.Label;
+
+import static com.intellij.openapi.compiler.CompilerMessageCategory.ERROR;
 
 /**
 * @author alex.tkachman
@@ -17,4 +25,23 @@ public class CompilationException extends RuntimeException {
     public PsiElement getElement() {
         return element;
     }
+
+    @Override
+    public String toString() {
+        PsiFile psiFile = element.getContainingFile();
+        TextRange textRange = element.getTextRange();
+        Document document = psiFile.getViewProvider().getDocument();
+        int line;
+        int col;
+        if (document != null) {
+            line = document.getLineNumber(textRange.getStartOffset());
+            col = textRange.getStartOffset() - document.getLineStartOffset(line) + 1;
+        }
+        else {
+            line = -1;
+            col = -1;
+        }
+
+        return "Internal error: (" + (line+1) + "," + col + ") " + getCause().toString();
+    }
 }