6879689: Fix warning about ignored return value when compiling with -O2
Summary: Store the return value of fwrite and check it matches the size of the array.
Reviewed-by: twisti, dholmes
6858208: jvm crash when specifying TypeProfileWidth=0 on jdk 6.0
Summary: Add an explicit check for TypeProfileWidth == 0 in record_klass_in_profile_helper() functions.
Reviewed-by: never, coleenp