[TESTBUG] java/util/HashMap/OverrideIsEmpty.java doesn't compile for jdk7u

there is no java.util.function.BiFunction class in 7u and the testcase needs updating.

command: compile -XDignore.symbol.file=true /opt/jprt/T/P1/165231.scoffey/s/jdk/test/java/util/HashMap/OverrideIsEmpty.java
reason: .class file out of date or does not exist
elapsed time (seconds): 0.09
direct:
/opt/jprt/T/P1/165231.scoffey/s/jdk/test/java/util/HashMap/OverrideIsEmpty.java:36: error: package java.util.function does not exist
import java.util.function.BiFunction;
                         ^
/opt/jprt/T/P1/165231.scoffey/s/jdk/test/java/util/HashMap/OverrideIsEmpty.java:69: error: cannot find symbol
        map.replace(key, value, null);
           ^
  symbol: method replace(Object,Object,<null>)
  location: variable map of type NotEmptyHashMap<Object,Object>
/opt/jprt/T/P1/165231.scoffey/s/jdk/test/java/util/HashMap/OverrideIsEmpty.java:70: error: cannot find symbol
        map.replace(key, value);
           ^
  symbol: method replace(Object,Object)
  location: variable map of type NotEmptyHashMap<Object,Object>
/opt/jprt/T/P1/165231.scoffey/s/jdk/test/java/util/HashMap/OverrideIsEmpty.java:71: error: cannot find symbol
        map.computeIfPresent(key, new BiFunction<Object, Object, Object>() {
                                      ^
  symbol: class BiFunction
  location: class OverrideIsEmpty
4 errors

TEST RESULT: Failed. Compilation failed: Compilation failed