Update text_painter.dart (#152398)

Reuse `RegExp`s in `TextPainter`.

Author: LongCatIsLooong

packages/flutter/lib/src/painting/text_painter.dart

@@ -219,6 +219,7 @@ class WordBoundary extends TextBoundary {
     };
   }
 
+  static final RegExp _regExpSpaceSeparatorOrPunctuaion = RegExp(r'[\p{Space_Separator}\p{Punctuation}]', unicode: true);
   bool _skipSpacesAndPunctuations(int offset, bool forward) {
     // Use code point since some punctuations are supplementary characters.
     // "inner" here refers to the code unit that's before the break in the
@@ -235,7 +236,7 @@ class WordBoundary extends TextBoundary {
     final bool hardBreakRulesApply = innerCodePoint == null || outerCodeUnit == null
     // WB3a & WB3b: always break before and after newlines.
                                   || _isNewline(innerCodePoint) || _isNewline(outerCodeUnit);
-    return hardBreakRulesApply || !RegExp(r'[\p{Space_Separator}\p{Punctuation}]', unicode: true).hasMatch(String.fromCharCode(innerCodePoint));
+    return hardBreakRulesApply || !_regExpSpaceSeparatorOrPunctuaion.hasMatch(String.fromCharCode(innerCodePoint));
   }
 
   /// Returns a [TextBoundary] suitable for handling keyboard navigation
@@ -332,6 +333,7 @@ class _TextLayout {
     };
   }
 
+  static final RegExp _regExpSpaceSeparators = RegExp(r'\p{Space_Separator}', unicode: true);
   /// The line caret metrics representing the end of text location.
   ///
   /// This is usually used when the caret is placed at the end of the text
@@ -364,7 +366,7 @@ class _TextLayout {
       0x00A0 ||         // no-break space
       0x2007 ||         // figure space
       0x202F => false,  // narrow no-break space
-      _ => RegExp(r'\p{Space_Separator}', unicode: true).hasMatch(lastCodeUnit),
+      _ => _regExpSpaceSeparators.hasMatch(lastCodeUnit),
     };
 
     final double baseline = lineMetrics.baseline;