Remove last vestiges of JAVASCRIPTCORE_PRIVATE_HEADERS_DIR from WebKit

    Remove last vestiges of JAVASCRIPTCORE_PRIVATE_HEADERS_DIR from WebKit

        Reviewed by Adam Roben.

        Use of JAVASCRIPTCORE_PRIVATE_HEADERS_DIR was removed in r37465
        since NPAPI headers had migrated from JavaScriptCore to WebCore
        before that.

WebKit:

        * WebKit.xcodeproj/project.pbxproj: Removed
        JAVASCRIPTCORE_PRIVATE_HEADERS_DIR build setting from from Debug
        and Release configurations.

WebKit/mac:

        * Configurations/WebKit.xcconfig: Removed definition of
        JAVASCRIPTCORE_PRIVATE_HEADERS_DIR used in Production builds.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@41409 268f45cc-cd09-0410-ab3c-d52691b4dbfc