mudflap problem

[Frank Ch. Eigler]

I wrote:

> This should not be happening, unless some intermediate compiler pass
> is lowering the ARRAY_REF (b[i]) to a plain INDIRECT_REF (* b+i)
> type expression.  [...]

It turns out that this lowering is occurring in the current
tree-mudflap.c code itself.  (See how ARRAY_REF is handled in
mf_build_check_statement_for().)  It used not to do that - I'm
investigating when/why this function became broken.

- FChE