Dip collection constants into device functions and loops

• Lower collection constants in CPU functions to memsets.
  • Remove FloatCollections from default pass order, GCM just runs once now.
• Dip collection constants inside loops instead of hoisting them when possible.
  • Gets rid of all spills in Cava, many in implict_clones.

requested review from @aaronjc4

assigned to @rarbore2

merged

mentioned in commit 213e6e71