Disable inlining and loop unrolling in LTO without PGO profile

Such optimisations may significantly increase the binary size when
compiler heuristics are off. Disabling these helps cut down the
binary sizes with negligible decrease in performance, but allows us to
be more comfortable enabling LTO across various projects.

Test: m
Test: dex2oat, hwui, skia benchmark
Bug: 62839002
Change-Id: Id63e8dd295df2972f76ae4e29ee367080fff8429