review for 7041582: set_mode_flags isn't called without -Xmixed specified

[Tom Rodriguez]

http://cr.openjdk.java.net/~never/7041582

7041582: set_mode_flags isn't called without -Xmixed specified
Reviewed-by:

The fix 7034513 moved some logic into set_mode_flags but
set_mode_flags isn't called unless a mode is specified on the command
line.  The fix simply to call set_mode_flag(_mixed) before parsing
arguments.  Tested with -XX:+PrintFlagsFinal.