[aarch64-port-dev ] RFR: JDK 7: Add support for large code cache

Hi, The following webrev adds support for large code caches (>128M) to JDK 7 for aarch64. http://cr.openjdk.java.net/~enevill/jdk7_largecode/webrev.01/ Tested with jtreg hotspot & langtools hotspot(original): Test results: passed: 297; failed: 12; error: 2 hotspot(256m cache): Test results: passed: 298; failed: 11; error: 2 langtools(original): Test results: passed: 1,973; failed: 1 langtools(256m cache): Test results: passed: 1,973; failed: 1 OK to push? Ed.