Fixes bugs in JCL implementation

teavm-classlib/src/main/java/org/teavm/classlib/java/io/TBufferedReader.java

@@ -85,7 +85,7 @@ public class TBufferedReader extends TReader {
 
     public TString readLine() throws TIOException {
         requireOpened();
-        if (eof && index == count) {
+        if (eof && index >= count) {
             return null;
         }
         TStringBuilder line = new TStringBuilder();

teavm-classlib/src/main/java/org/teavm/classlib/java/lang/MathNativeGenerator.java

@@ -28,21 +28,7 @@ import org.teavm.model.MethodReference;
 public class MathNativeGenerator implements Generator {
     @Override
     public void generate(GeneratorContext context, SourceWriter writer, MethodReference methodRef) throws IOException {
-        switch (methodRef.getName()) {
-            case "sin":
-            case "cos":
-            case "tan":
-            case "asin":
-            case "acos":
-            case "atan":
-            case "exp":
-            case "log":
-            case "sqrt":
-            case "floor":
-            case "ceil":
-                function(context, writer, "Math." + methodRef.getName(), methodRef.parameterCount());
-                break;
-        }
+        function(context, writer, "Math." + methodRef.getName(), methodRef.parameterCount());
     }
 
     private void function(GeneratorContext context, SourceWriter writer, String name, int paramCount)

teavm-classlib/src/main/java/org/teavm/classlib/java/util/TArrays.java

@@ -1492,6 +1492,11 @@ public class TArrays extends TObject {
             @Override public T get(int index) {
                 return a[index];
             }
+            @Override public T set(int index, T element) {
+                T old = a[index];
+                a[index] = element;
+                return old;
+            }
             @Override public int size() {
                 return a.length;
             }