Added some very limited reporting when OutOfMemorErrors occur during

parse tree builder under javac. Let's hope our users reporting these
issues can use this to figure out which files are triggering the issue.

src/core/lombok/javac/JavacAST.java

@@ -315,9 +315,18 @@ public class JavacAST extends AST<JavacAST, JavacNode, JCTree> {
 	}
 	
 	private JavacNode drill(JCTree statement) {
-		List<JavacNode> childNodes = new ArrayList<JavacNode>();
-		for (FieldAccess fa : fieldsOf(statement.getClass())) childNodes.addAll(buildWithField(JavacNode.class, statement, fa));
-		return putInMap(new JavacNode(this, statement, childNodes, Kind.STATEMENT));
+		try {
+			List<JavacNode> childNodes = new ArrayList<JavacNode>();
+			for (FieldAccess fa : fieldsOf(statement.getClass())) childNodes.addAll(buildWithField(JavacNode.class, statement, fa));
+			return putInMap(new JavacNode(this, statement, childNodes, Kind.STATEMENT));
+		} catch (OutOfMemoryError oome) {
+			String msg = oome.getMessage();
+			if (msg == null) msg = "(no original message)";
+			OutOfMemoryError newError = new OutOfMemoryError(getFileName() + "@pos" + statement.getPreferredPosition() + ": " + msg);
+			// We could try to set the stack trace of the new exception to the same one as the old exception, but this costs memory,
+			// and we're already in an extremely fragile situation in regards to remaining heap space, so let's not do that.
+			throw newError;
+		}
 	}
 	
 	/** For javac, both JCExpression and JCStatement are considered as valid children types. */