util/CharUtil: add IsWhitespaceFast()

src/util/CharUtil.hxx

@@ -58,6 +58,19 @@ IsWhitespaceNotNull(const char ch)
 	return ch > 0 && ch <= 0x20;
 }
 
+/**
+ * Is the given character whitespace?  This calls the faster one of
+ * IsWhitespaceOrNull() or IsWhitespaceNotNull().  Use this if you
+ * want the fastest implementation, and you don't care if a null byte
+ * matches.
+ */
+constexpr
+static inline bool
+IsWhitespaceFast(const char ch)
+{
+	return IsWhitespaceOrNull(ch);
+}
+
 constexpr
 static inline bool
 IsPrintableASCII(char ch)