tree-optimization/99746 - avoid confusing hybrid code

tree-optimization/99746 - avoid confusing hybrid code

This avoids confusing the hybrid vectorization code with SLP
patterns by not marking SLP pattern covered stmts as patterns
(they are marked as SLP patterns already).  This means that loop
vectorization will vectorize the scalar stmt rather than the SLP
pattern stmt (which it can't anyway).

2021-03-24  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/99746
	* tree-vect-slp-patterns.c (complex_pattern::build): Do not mark
	the scalar stmt as patterned.  Instead set up required things
	manually.

	* gfortran.dg/vect/pr99746.f90: New testcase.