280x compiler error with unused automatic and __byte() intrinsic

I submitted this issue via the support form on the web, but I was asked to repost it here.

The 280x compiler(v5.2.6) generates an internal error related to the use of __byte() intrinsic,
unread automatic variable, and optimizer.  If the optimizer is not used, the
error does not occur.

Here's a forum thread where someone else was encountering the same error.

http://e2e.ti.com/support/microcontrollers/tms320c2000_32-bit_real-time_mcus/f/171/p/21632/83599.aspx

Compiler the following code with this command line:
cl2000 -c -O2 -v28 foo.c

extern int c[10];

extern int y;

/* No error for this function. */
void
bar(void)
{
  if (__byte(c, 1))
    y = 1;
}


/* Compiling this code with any level of optimization causes the
   following compiler error:
     INTERNAL ERROR: no match for MCALL  */
void
foo(void)
{
  int x;

  if (__byte(c, 1))
    x = 1;
}