Description:
------------
When using FFI, very little useful debugging information is provided when type checking arguments for function calls/etc. 

In the test script, the syntax for fprintf is FILE*, const char*, ...

I made a "mistake" by passing a number for the second argument. FFI gave me no indication as to which parameter was incorrect, leading to either trial-and-error debugging, or breaking out GDB to see which argument was the problem. 

Test script:
---------------
<?php

$header = '
typedef struct _IO_FILE FILE;
extern FILE *stdout;
extern FILE *stdin;
extern FILE *stderr;

int fprintf(FILE *, const char *, ...);
';

$ffi = FFI::cdef($header, 'libc.so.6');

$ffi->fprintf($ffi->stdout, 123, "Hello %s\n", "World");

Expected result:
----------------
Fatal error: Uncaught FFI\Exception: Passing incompatible pointer to argument 2 of function fprintf, expecting const char*, found long long in /.../test.php:14
Stack trace:
#0 /.../test.php(14): FFI->fprintf(Object(FFI\CData:<struct>*), 123, 'Hello %s\n', 'World')
#1 {main}
  thrown in /.../test.php on line 14


Actual result:
--------------
Fatal error: Uncaught FFI\Exception: Passing incompatible pointer in /.../test.php:14
Stack trace:
#0 /.../test.php(14): FFI->fprintf(Object(FFI\CData:<struct>*), 123, 'Hello %s\n', 'World')
#1 {main}
  thrown in /.../test.php on line 14