ICU-21833 Replace U_FINAL with final everywhere.

icu4c/source/Doxyfile.in

@@ -2085,8 +2085,7 @@ PREDEFINED             = U_EXPORT2= \
                          U_IN_DOXYGEN=1 \
                          U_CHAR16_IS_TYPEDEF=0 \
                          U_CPLUSPLUS_VERSION=11 \
-                         U_WCHAR_IS_UTF16 \
-                         U_FINAL=final
+                         U_WCHAR_IS_UTF16
 
 # If the MACRO_EXPANSION and EXPAND_ONLY_PREDEF tags are set to YES then this
 # tag can be used to specify a list of macro names that should be expanded. The

icu4c/source/common/unicode/caniter.h

@@ -73,7 +73,7 @@ Results for: {LATIN CAPITAL LETTER A WITH RING ABOVE}{LATIN SMALL LETTER D}{COMB
  * @author C++ port by V. Weinstein
  * @stable ICU 2.4
  */
-class U_COMMON_API CanonicalIterator U_FINAL : public UObject {
+class U_COMMON_API CanonicalIterator final : public UObject {
 public:
     /**
      * Construct a CanonicalIterator object

icu4c/source/common/unicode/casemap.h

@@ -30,7 +30,7 @@ class Edits;
  *
  * @stable ICU 59
  */
-class U_COMMON_API CaseMap U_FINAL : public UMemory {
+class U_COMMON_API CaseMap final : public UMemory {
 public:
     /**
      * Lowercases a UTF-16 string and optionally records edits.

icu4c/source/common/unicode/char16ptr.h

@@ -39,7 +39,7 @@ U_NAMESPACE_BEGIN
  * char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
  * @stable ICU 59
  */
-class U_COMMON_API Char16Ptr U_FINAL {
+class U_COMMON_API Char16Ptr final {
 public:
     /**
      * Copies the pointer.
@@ -146,7 +146,7 @@ char16_t *Char16Ptr::get() const { return u_.cp; }
  * const char16_t * wrapper with implicit conversion from distinct but bit-compatible pointer types.
  * @stable ICU 59
  */
-class U_COMMON_API ConstChar16Ptr U_FINAL {
+class U_COMMON_API ConstChar16Ptr final {
 public:
     /**
      * Copies the pointer.

icu4c/source/common/unicode/edits.h

@@ -77,7 +77,7 @@ class UnicodeString;
  *
  * @stable ICU 59
  */
-class U_COMMON_API Edits U_FINAL : public UMemory {
+class U_COMMON_API Edits final : public UMemory {
 public:
     /**
      * Constructs an empty object.
@@ -200,7 +200,7 @@ public:
      * @see getFineIterator
      * @stable ICU 59
      */
-    struct U_COMMON_API Iterator U_FINAL : public UMemory {
+    struct U_COMMON_API Iterator final : public UMemory {
         /**
          * Default constructor, empty iterator.
          * @stable ICU 60

icu4c/source/common/unicode/rbbi.h

@@ -54,7 +54,7 @@ class  UStack;
  *
  * <p>This class is not intended to be subclassed.</p>
  */
-class U_COMMON_API RuleBasedBreakIterator /*U_FINAL*/ : public BreakIterator {
+class U_COMMON_API RuleBasedBreakIterator /*final*/ : public BreakIterator {
 
 private:
     /**

icu4c/source/common/unicode/simpleformatter.h

@@ -59,7 +59,7 @@ class SimpleModifier;
  * @see UMessagePatternApostropheMode
  * @stable ICU 57
  */
-class U_COMMON_API SimpleFormatter U_FINAL : public UMemory {
+class U_COMMON_API SimpleFormatter final : public UMemory {
 public:
     /**
      * Default constructor.

icu4c/source/common/unicode/umachine.h

@@ -119,17 +119,6 @@
 /** Obsolete/same as U_CAPI; was used to declare a function as an internal ICU C API  */
 #define U_INTERNAL U_CAPI
 
-/**
- * \def U_FINAL
- * Defined to the C++11 "final" keyword if available.
- * Denotes a class or member which may not be overridden in subclasses.
- * May result in an error if subclasses attempt to override.
- * @internal
- */
-#if !defined(U_FINAL) || defined(U_IN_DOXYGEN)
-#define U_FINAL final
-#endif
-
 // Before ICU 65, function-like, multi-statement ICU macros were just defined as
 // series of statements wrapped in { } blocks and the caller could choose to
 // either treat them as if they were actual functions and end the invocation

icu4c/source/common/unicode/uniset.h

@@ -282,7 +282,7 @@ class RuleCharacterIterator;
  * @author Alan Liu
  * @stable ICU 2.0
  */
-class U_COMMON_API UnicodeSet U_FINAL : public UnicodeFilter {
+class U_COMMON_API UnicodeSet final : public UnicodeFilter {
 private:
     /**
      * Enough for sets with few ranges.

icu4c/source/common/unicode/usetiter.h

@@ -64,7 +64,7 @@ class UnicodeString;
  * @author M. Davis
  * @stable ICU 2.4
  */
-class U_COMMON_API UnicodeSetIterator U_FINAL : public UObject {
+class U_COMMON_API UnicodeSetIterator final : public UObject {
     /**
      * Value of <tt>codepoint</tt> if the iterator points to a string.
      * If <tt>codepoint == IS_STRING</tt>, then examine

icu4c/source/i18n/unicode/coleitr.h

@@ -118,7 +118,7 @@ class UVector32;
 * @see     RuleBasedCollator
 * @version 1.8 Jan 16 2001
 */
-class U_I18N_API CollationElementIterator U_FINAL : public UObject {
+class U_I18N_API CollationElementIterator final : public UObject {
 public: 
 
     // CollationElementIterator public data member ------------------------------

icu4c/source/i18n/unicode/dtfmtsym.h

@@ -81,7 +81,7 @@ class Hashtable;
  * locale at least contains any resources that are to be particularized for the
  * calendar type.
  */
-class U_I18N_API DateFormatSymbols U_FINAL : public UObject  {
+class U_I18N_API DateFormatSymbols final : public UObject  {
 public:
     /**
      * Construct a DateFormatSymbols object by loading format data from

icu4c/source/i18n/unicode/dtitvinf.h

@@ -151,7 +151,7 @@ U_NAMESPACE_BEGIN
  * calendar; non-Gregorian calendars are supported from ICU 4.4.1.
  * @stable ICU 4.0
 **/
-class U_I18N_API DateIntervalInfo U_FINAL : public UObject {
+class U_I18N_API DateIntervalInfo final : public UObject {
 public:
     /**
      * Default constructor.

icu4c/source/i18n/unicode/regex.h

@@ -84,7 +84,7 @@ class  UVector64;
   *
   * @stable ICU 2.4
   */
-class U_I18N_API RegexPattern U_FINAL : public UObject {
+class U_I18N_API RegexPattern final : public UObject {
 public:
 
     /**
@@ -656,7 +656,7 @@ private:
  *
  * @stable ICU 2.4
  */
-class U_I18N_API RegexMatcher U_FINAL : public UObject {
+class U_I18N_API RegexMatcher final : public UObject {
 public:
 
     /**

icu4c/source/i18n/unicode/stsearch.h

@@ -132,7 +132,7 @@ U_NAMESPACE_BEGIN
  * @since ICU 2.0
  */
 
-class U_I18N_API StringSearch U_FINAL : public SearchIterator
+class U_I18N_API StringSearch final : public SearchIterator
 {
 public:
 

icu4c/source/i18n/unicode/tblcoll.h

@@ -112,7 +112,7 @@ class UVector64;
  * Note, RuleBasedCollator is not to be subclassed.
  * @see        Collator
  */
-class U_I18N_API RuleBasedCollator U_FINAL : public Collator {
+class U_I18N_API RuleBasedCollator final : public Collator {
 public:
     /**
      * RuleBasedCollator constructor. This takes the table rules and builds a