RFR(S): 8038268: VM Crashes in MetaspaceShared::generate_vtable_methods while creating CDS archive with limiting SharedMiscCodeSize

[Calvin Cheung]

JBS: https://bugs.openjdk.java.net/browse/JDK-8038268

The fix is to estimate the minimum required size for the misc code 
region based on the instructions in the x64 version of 
MetaspaceShared::generate_vtable_methods(). If the user's specified misc 
code size is less than the minimum required size, the vm will issue an 
error message instead of crashing.

With the fix, the error message will be:
./bin/java -XX:+UnlockDiagnosticVMOptions 
-XX:SharedArchiveFile=./test.jsa -XX:SharedMiscCodeSize=32k -Xshare:dump
Java HotSpot(TM) 64-Bit Server VM warning:
The shared miscellaneous code space is not large enough
to preload requested classes. Use -XX:SharedMiscCodeSize=
to increase the initial size of shared miscellaneous code space.

webrev: http://cr.openjdk.java.net/~ccheung/8038268/jdk9/webrev/

Test:
     JPRT
     jtreg on the affected test on linux_x64 and windows_x64.

thanks,
Calvin