Update nightly to conditionally build with optimizations.
Update nightly to conditionally build with optimizations.

Update nightly to check host compiler and build without optimizations for cray
compiler. This is an experiment to see if it stabilizes the tests for this
compiler.

chizarlicious/chapel,chizarlicious/chapel,chizarlicious/chapel,hildeth/chapel,chizarlicious/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,hildeth/chapel,chizarlicious/chapel,hildeth/chapel,hildeth/chapel,CoryMcCartan/chapel,chizarlicious/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,CoryMcCartan/chapel,chizarlicious/chapel