Temporary fix: ensure macros.unit is not deallocated inside of unitIsBaseUnit

Author: iCharlesHu

icuSources/i18n/number_formatimpl.cpp

@@ -133,8 +133,9 @@ NumberFormatterImpl::macrosToMicroGenerator(const MacroProps& macros, bool safe,
     // TODO: Accept currency symbols from DecimalFormatSymbols?
 
     // Pre-compute a few values for efficiency.
+    auto unit = macros.unit;
     bool isCurrency = utils::unitIsCurrency(macros.unit);
-    bool isBaseUnit = utils::unitIsBaseUnit(macros.unit);
+    bool isBaseUnit = utils::unitIsBaseUnit(unit);
     bool isPercent = utils::unitIsPercent(macros.unit);
     bool isPermille = utils::unitIsPermille(macros.unit);
     bool isCompactNotation = macros.notation.fType == Notation::NTN_COMPACT;