* add linux-oe-g++ mkspec directly with patch
* add functions to read and eval OE_QMAKE functions from mkspec and
also export them with QMakeVar to be available also for config.tests
* add external-host-bindir parameter to skip building native tools
even when we're in fact cross-compiling (because we have them from
qtbase-native build already).
* use separated ${B} and ${S} and clean ${B} when reconfiguring
stalled qmake cache can be used when configure is reexecuted
cleaning ${B} prevents that and provide cleaner separation
* OE_QMAKE_AR cqs is added by Makefile, having it here too was causing
issues
* isEmpty(QT_EXTERNAL_HOST_BINS) doesn't work, so lets use exist()
even when it allows to incorrectly set wrong directory and build
native tools again (instead of skipping them)
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Martin Jansa