ICU-22897 Fix memory leak and int overflow #99

Job	Run time
icu4c-store-perf-libs	0s
icu4c-windows-cygwin-gcc	24m 51s
icu4c-windows-msvc-postmerge (x64, Debug)	10m 7s
icu4j-mvn-init-cache	45s
icu4c-windows-msvc-postmerge (x64, Release)	7m 53s
icu4c-windows-msvc-postmerge (x86, Debug)	12m 41s
icu4c-windows-msvc-postmerge (x86, Release)	8m 27s
icu4c-performance-tests	0s
icu4c-performance-tests-with-files	0s
icu4c-strsrchperf	0s
icu4j-little-endian-data-test	10m 44s
icu4j-decimalformatperf	0s
icu4j-unicodesetperf	0s
icu4j-converterperf	0s
icu4j-dateformatperf	0s
icu4j-normperf	0s
icu4j-ucharacterperf	0s
Copy perf data to remote repo for visualization	0s
	1h 15m 28s

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