[Bug target/84907] [8 Regression] ppc64le gromacs miscompilation since r256656

[kelvin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84907

--- Comment #3 from kelvin at gcc dot gnu.org ---
The Power backend will assume that any pointer declared as pointer to vector is
aligned to the vector size.  Coercing a (float *) to a (vector float *)
violates this assumption.  The code as written is not valid.