hg: jdk6/jdk6/jdk: 7128505: Building on em64t system does not work

[kelly . ohair]

Changeset: ef3efe6d9488
Author:    ohair
Date:      2012-01-09 19:10 -0800
URL:       http://hg.openjdk.java.net/jdk6/jdk6/jdk/rev/ef3efe6d9488

7128505: Building on em64t system does not work
Reviewed-by: darcy

! make/common/shared/Platform.gmk