Enable --warn-insts-with-functors-without-type.

configure.ac:
    Require that the installed compiler support this option (which I added
    about two weeks ago).

browser/MDB_FLAGS.in:
compiler/COMP_FLAGS.in:
deep_profiler/DEEP_FLAGS.in:
library/LIB_FLAGS.in:
mdbcomp/MDBCOMP_FLAGS.in:
mfilterjavac/MFILTERJAVAC_FLAGS.in:
profiler/PROF_FLAGS.in:
slice/SLICE_FLAGS.in:
ssdb/SSDB_FLAGS.in:
    Specify this option by default for every directory that contains
    Mercury code.

mfilterjavac/MFILTERJAVAC_FLAGS.in

@@ -3,6 +3,7 @@
 --warn-known-bad-format-calls
 --warn-unknown-format-calls
 --warn-unused-imports
+--warn-insts-with-functors-without-type
 --halt-at-warn
 --no-warn-inferred-erroneous
 --no-mercury-stdlib-dir