Fix CompareInfo.IsPrefix/IsSuffix with CompareOptions.IgnoreSymbols not ignoring leading/trailing symbols

src/libraries/System.Runtime/tests/System.Globalization.Tests/CompareInfo/CompareInfoTests.IsPrefix.cs

@@ -87,8 +87,7 @@ public static IEnumerable<object[]> IsPrefix_TestData()
             else
             {
                 yield return new object[] { s_hungarianCompare, "dzsdzsfoobar", "ddzsf", CompareOptions.None, false, 0 };
-                // Bug in ICU (non-Apple) implementation, correct result should be true (https://github.com/dotnet/runtime/issues/118521)
-                yield return new object[] { s_invariantCompare, "''Tests", "Tests", CompareOptions.IgnoreSymbols, PlatformDetection.IsHybridGlobalizationOnApplePlatform ? true : false, 0 };
+                yield return new object[] { s_invariantCompare, "''Tests", "Tests", CompareOptions.IgnoreSymbols, true, 7 };
                 yield return new object[] { s_frenchCompare, "\u0153", "oe", CompareOptions.None, false, 0 };
                 if (PlatformDetection.IsNotHybridGlobalizationOnApplePlatform)
                 {

src/libraries/System.Runtime/tests/System.Globalization.Tests/CompareInfo/CompareInfoTests.IsSuffix.cs

@@ -81,6 +81,7 @@ public static IEnumerable<object[]> IsSuffix_TestData()
 
             // Ignore symbols
             yield return new object[] { s_invariantCompare, "More Test's", "Tests", CompareOptions.IgnoreSymbols, true, 6 };
+            yield return new object[] { s_invariantCompare, "Tests''", "Tests", CompareOptions.IgnoreSymbols, true, 7 };
             yield return new object[] { s_invariantCompare, "More Test's", "Tests", CompareOptions.None, false, 0 };
 
             // NULL character

src/native/libs/System.Globalization.Native/pal_collation.c

@@ -407,29 +407,14 @@ static UCollator* CloneCollatorWithOptions(const UCollator* pCollator, int32_t o
     return pClonedCollator;
 }
 
-// Returns TRUE if all the collation elements in str are completely ignorable
+// Returns TRUE if str is completely ignorable by the collator.
 static int CanIgnoreAllCollationElements(const UCollator* pColl, const UChar* lpStr, int32_t length)
 {
-    int result = true;
-    UErrorCode err = U_ZERO_ERROR;
-    UCollationElements* pCollElem = ucol_openElements(pColl, lpStr, length, &err);
-
-    if (U_SUCCESS(err))
-    {
-        int32_t curCollElem = UCOL_NULLORDER;
-        while ((curCollElem = ucol_next(pCollElem, &err)) != UCOL_NULLORDER)
-        {
-            if (curCollElem != UCOL_IGNORABLE)
-            {
-                result = false;
-                break;
-            }
-        }
-
-        ucol_closeElements(pCollElem);
-    }
-
-    return U_SUCCESS(err) ? result : false;
+    // Collation element iterators expose raw elements and do not apply shifted
+    // alternate handling. Compare against an empty string so all collator
+    // options, including IgnoreSymbols, are honored.
+    UChar emptyString = 0;
+    return ucol_strcoll(pColl, lpStr, length, &emptyString, 0) == UCOL_EQUAL;
 }
 
 static void CreateSortHandle(SortHandle** ppSortHandle)