In open-source Guava, completely skip trying to discover pluggable Pa…

…tternCompiler implementations.

It's never been possible to create such implementations externally, anyway, and users are now seeing problems running the useless discovery code under the module system.

Fixes #3147

RELNOTES=`base`: Fixed the `ServiceConfigurationError` that some users encountered when using Guava as a JPMS module.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=198449885

guava/src/com/google/common/base/Platform.java

@@ -16,10 +16,8 @@
 
 import com.google.common.annotations.GwtCompatible;
 import java.lang.ref.WeakReference;
-import java.util.Iterator;
 import java.util.Locale;
 import java.util.ServiceConfigurationError;
-import java.util.ServiceLoader;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import java.util.regex.Pattern;
@@ -77,20 +75,6 @@ static boolean usingJdkPatternCompiler() {
   }
 
   private static PatternCompiler loadPatternCompiler() {
-    ServiceLoader<PatternCompiler> loader = ServiceLoader.load(PatternCompiler.class);
-    // Returns the first PatternCompiler that loads successfully.
-    try {
-      for (Iterator<PatternCompiler> it = loader.iterator(); it.hasNext(); ) {
-        try {
-          return it.next();
-        } catch (ServiceConfigurationError e) {
-          logPatternCompilerError(e);
-        }
-      }
-    } catch (ServiceConfigurationError e) { // from hasNext()
-      logPatternCompilerError(e);
-    }
-    // Fall back to the JDK regex library.
     return new JdkPatternCompiler();
   }