Require CCACHE_SLOPPINESS=pch_defines when creating precompiled header

708d9110a103bd49437be7bff1e82697fff68d0b introduced the requirement of
sloppy pch_defines for using a PCH, but it's the act of creating (and
storing in the cache) a PCH that needs to be opt-in.
Merge branch 'maint'

* maint:
  Require CCACHE_SLOPPINESS=pch_defines when creating precompiled header

Conflicts:
	ccache.c
	test.sh