Replace alternating regex with character classes

This commit replaces two alternating regular expressions (that is,
regular expressions that consist of the form a|b where a and b are
characters) with the equivalent regular expression rewritten as a
character class (that is, [ab]) The reason this is an improvement is
because a|b involves backtracking while [ab] does not.

Relates #24316

core/src/main/java/org/elasticsearch/Version.java

@@ -196,7 +196,7 @@ public class Version implements Comparable<Version> {
         if (snapshot = version.endsWith("-SNAPSHOT")) {
             version = version.substring(0, version.length() - 9);
         }
-        String[] parts = version.split("\\.|\\-");
+        String[] parts = version.split("[.-]");
         if (parts.length < 3 || parts.length > 4) {
             throw new IllegalArgumentException(
                     "the version needs to contain major, minor, and revision, and optionally the build: " + version);

core/src/main/java/org/elasticsearch/common/logging/DeprecationLogger.java

@@ -311,7 +311,7 @@ public class DeprecationLogger {
      * @return the escaped string
      */
     public static String escape(String s) {
-        return s.replaceAll("(\\\\|\")", "\\\\$1");
+        return s.replaceAll("([\"\\\\])", "\\\\$1");
     }
 
 }