It's not thread-safe so should only be used within systemData()'s
locked code. This eliminates the last callers of it by making it a
local function of the compilation unit, exposing a method from
QSystemLocale() to get round its use of private parts. Make the
constructor for QSystemLocale only stomp its _systemLocale global if
previously unset, but let instantiation still clear
globalLocaleData.m_language_id, so that it can be used as a way to
trigger an update to system locale data.
Change-Id: I908dca9fd30bbf20f42321ab8f9094f2fa37b7b0
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
d5891036de