Bump to Java 11

[rbygrave]

JVM option +AggressiveOpts is not supported with Java 11

./run -t 8 ser --apis databind --libs dsljson,jackson,avajejsonb
...

Benchmark                           Mode  Cnt        Score        Error  Units
Serialization.avajejsonb           thrpt   20  1585076.847 ±  36652.798  ops/s
Serialization.avajejsonb_jackson   thrpt   20  1213119.133 ±  38043.554  ops/s
Serialization.dsljson              thrpt   20  2105699.862 ± 170635.410  ops/s
Serialization.dsljson_reflection   thrpt   20  1222861.457 ± 183719.804  ops/s
Serialization.jackson              thrpt   20   849187.430 ±  36890.232  ops/s
Serialization.jackson_afterburner  thrpt   20   918967.302 ±  20334.650  ops/s

./run -t 8 deser --apis databind --libs dsljson,jackson,avajejsonb
...

Benchmark                             Mode  Cnt       Score        Error  Units
Deserialization.avajejsonb           thrpt   20  868045.014 ±  17977.578  ops/s
Deserialization.avajejsonb_jackson   thrpt   20  584279.347 ±  19173.005  ops/s
Deserialization.dsljson              thrpt   20  890778.545 ± 117956.756  ops/s
Deserialization.dsljson_reflection   thrpt   20  717535.068 ±  78193.330  ops/s
Deserialization.jackson              thrpt   20  594409.019 ±  22062.293  ops/s
Deserialization.jackson_afterburner  thrpt   20  709780.268 ±  22885.685  ops/s