AST Parser: Print filename when reporting error

[Stephen Siegel]

Can the AST Parser print the file name of the file with the error instead of the Java gobly-gook:

An XML parse error occurred while parsing java.io.FileInputStream@7a03411a line 38 column 50

[stachnik]

This error should no longer appear when ASTParsers are created through the new ASTs.makeASTParser() method.