Revert "Do materialize for floating point"

1) The commit was made despite profound lack of understanding:

   "I did not understand the comment about using dyn_cast instead of isa. I will
   commit as is and make the update after. You can explain what you meant to me."

   Commit first, understand later isn't OK.

2) Review comments were simply ignored:

   "Can you edit the summary to describe what the patch is for? It appears to be
   a list of commits at the moment."

3) The patch got LGTM'd off-list without any indication of readiness.

4) The public mailing list was excluded from patch review so all of this was
   hidden from the community.

This reverts commit r210414.

llvm-svn: 210424