ICU-23265 Tried to address build failures and code review comments.

Author: richgillam

icu4c/source/test/depstest/dependencies.txt

@@ -1135,7 +1135,7 @@ group: units_extra
 group: units
     measunit.o currunit.o
   deps
-    stringenumeration errorcode
+    stringenumeration errorcode units_extra
 
 group: unitsformatter
     units_data.o units_converter.o units_complexconverter.o units_router.o

icu4j/main/core/src/main/java/com/ibm/icu/number/NumberSkeletonImpl.java

@@ -1094,20 +1094,11 @@ private static void parseMeasureUnitOption(StringSegment segment, MacroProps mac
             }
             String type = segment.subSequence(0, firstHyphen).toString();
             String subType = segment.subSequence(firstHyphen + 1, segment.length()).toString();
-            MeasureUnit unit = MeasureUnit.getUnit(type, subType);
+            MeasureUnit unit = MeasureUnit.validateAndGet(type, subType);
             if (unit != null) {
                 macros.unit = unit;
                 return;
             }
-            try {
-                unit = MeasureUnit.forIdentifier(subType);
-                if (unit.getType().equals(type)) {
-                    macros.unit = unit;
-                    return;
-                }
-            } catch (IllegalArgumentException e) {
-                // handled below
-            }
 
             throw new SkeletonSyntaxException("Unknown measure unit", segment);
         }

icu4j/main/core/src/main/java/com/ibm/icu/util/MeasureUnit.java

@@ -889,6 +889,23 @@ public static MeasureUnit getUnit(String type, String subtype) {
         Map<String, MeasureUnit> units = cache.get(type);
         return units != null ? units.get(subtype) : null;
     }
+    
+    @Deprecated
+    public static MeasureUnit validateAndGet(String type, String subtype) {
+    	MeasureUnit result = MeasureUnit.getUnit(type, subtype);
+    	
+    	if (result == null) {
+            try {
+                result = MeasureUnit.forIdentifier(subtype);
+                if (!result.getType().equals(type)) {
+                	result = null;
+                }
+            } catch (IllegalArgumentException e) {
+                // leave result as null
+            }
+        }
+        return result;
+    }
 
     static final UnicodeSet ASCII = new UnicodeSet('a', 'z').freeze();
     static final UnicodeSet ASCII_HYPHEN_DIGITS =

icu4j/main/core/src/test/java/com/ibm/icu/dev/test/number/NumberSkeletonTest.java

@@ -555,22 +555,23 @@ public void unitAliases() {
         class TestCase {
             String skeleton;
             String expectedResult;
+
             TestCase(String skeleton, String expectedResult) {
                 this.skeleton = skeleton;
                 this.expectedResult = expectedResult;
             }
         }
 
         TestCase[] testCases =
-            new TestCase[] {
-                new TestCase("measure-unit/concentr-part-per-1e6", "3.14 ppm"),
-                new TestCase("measure-unit/concentr-part-per-million", "3.14 ppm"),
-                new TestCase("measure-unit/concentr-permillion", "3.14 ppm"),
-                new TestCase("measure-unit/concentr-milligram-ofglucose-per-deciliter", "3.14 mg/dL"),
-                new TestCase("measure-unit/concentr-milligram-per-deciliter", "3.14 mg/dL"),
-                new TestCase("measure-unit/mass-tonne", "3.14 t"),
-                new TestCase("measure-unit/mass-metric-ton", "3.14 t"),
-            };
+                new TestCase[] {
+                    new TestCase("measure-unit/concentr-part-per-1e6", "3.14 ppm"),
+                    new TestCase("measure-unit/concentr-part-per-million", "3.14 ppm"),
+                    new TestCase("measure-unit/concentr-permillion", "3.14 ppm"),
+                    new TestCase("measure-unit/concentr-milligram-ofglucose-per-deciliter", "3.14 mg/dL"),
+                    new TestCase("measure-unit/concentr-milligram-per-deciliter", "3.14 mg/dL"),
+                    new TestCase("measure-unit/mass-tonne", "3.14 t"),
+                    new TestCase("measure-unit/mass-metric-ton", "3.14 t"),
+                };
 
         for (TestCase testCase : testCases) {
             try {