ICU-22983 Fix DecimalQuantity::shiftLeft ubsan issue

[FrankYFTang]

Fix undefined behavior of shifting 64 bits in uint64 type

Checklist

• Required: Issue filed: ICU-22983
• Required: The PR title must be prefixed with a JIRA Issue number. Example: "ICU-1234 Fix xyz"
• Required: The PR description must include the link to the Jira Issue, for example by completing the URL in the first checklist item
• Required: Each commit message must be prefixed with a JIRA Issue number. Example: "ICU-1234 Fix xyz"
• Issue accepted (done by Technical Committee after discussion)
• Tests included, if applicable
• API docs and/or User Guide docs changed or added, if applicable

[markusicu]

Could you please check the Java code?

[jira-pull-request-webhook]

Notice: the branch changed across the force-push!

• icu4j/main/common_tests/src/test/java/com/ibm/icu/dev/test/format/NumberRegressionTests.java is now changed in the branch
• icu4j/main/core/src/main/java/com/ibm/icu/impl/number/DecimalQuantity_DualStorageBCD.java is now changed in the branch

View Diff Across Force-Push

~ Your Friendly Jira-GitHub PR Checker Bot

[FrankYFTang]

Java comments and tests added. The story about java is more interesting but the solution is the same .