ticket:10483: Further #ifndef U_HIDE_XXX adjustments from running hdrtst

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@34966 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10644 Add missing #include of platform.h

git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@34968 251d0590-4201-4cf1-90de-194747b24ca1
ticket:10483: Fix no data test errors in ICU4C 53m1


git-svn-id: http://source.icu-project.org/repos/icu/icu/trunk/source@34979 251d0590-4201-4cf1-90de-194747b24ca1