ICU-13219 add -u-dx support to BreakIterator #3026

Job	Run time
clang-valgrind-test	10m 12s
clang-valgrind-intltest (utility)	6m 44s
clang-valgrind-intltest (normalize)	6m 18s
clang-valgrind-intltest (collator)	5m 57s
clang-valgrind-intltest (regex)	5m 25s
clang-valgrind-intltest (format)	16m 8s
clang-valgrind-intltest (translit)	6m 6s
clang-valgrind-intltest (rbbi)	7m 31s
clang-valgrind-intltest (rbnf)	6m 39s
clang-valgrind-intltest (rbnfrt)	6m 17s
clang-valgrind-intltest (icuserv)	5m 18s
clang-valgrind-intltest (idna)	5m 35s
clang-valgrind-intltest (convert)	6m 18s
clang-valgrind-intltest (rbnfp)	5m 20s
clang-valgrind-intltest (csdet)	5m 52s
clang-valgrind-intltest (spoof)	4m 51s
clang-valgrind-intltest (bidi)	5m 41s
	1h 56m 12s

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