ICU-13219 add -u-dx support to BreakIterator #1202

Job	Run time
clang-valgrind-test	10m 36s
clang-valgrind-intltest (utility)	6m 43s
clang-valgrind-intltest (normalize)	5m 53s
clang-valgrind-intltest (collator)	5m 11s
clang-valgrind-intltest (regex)	5m 48s
clang-valgrind-intltest (format)	16m 25s
clang-valgrind-intltest (translit)	5m 52s
clang-valgrind-intltest (rbbi)	7m 28s
clang-valgrind-intltest (rbnf)	6m 13s
clang-valgrind-intltest (rbnfrt)	6m 2s
clang-valgrind-intltest (icuserv)	4m 54s
clang-valgrind-intltest (idna)	5m 30s
clang-valgrind-intltest (convert)	6m 32s
clang-valgrind-intltest (rbnfp)	5m 9s
clang-valgrind-intltest (csdet)	5m 12s
clang-valgrind-intltest (spoof)	5m 1s
clang-valgrind-intltest (bidi)	5m 7s
	1h 53m 36s

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