world: rework cmake sanity and sysroot alignment

This is a panic commit in the middle of development - have the feeling my host
dies...

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>

classes/cmake_native_dummy.bbclass

@@ -0,0 +1,22 @@
+#
+# Class to create dummy native binaries so cmake can reference them
+# Inspired by binconfig-disabled.bbclass
+#
+
+inherit native
+
+# The list of scripts which should be disabled.
+CMAKE_DUMMY_BINARIES ?= ""
+
+do_install () {
+    install -d ${D}${bindir}
+    for x in ${CMAKE_DUMMY_BINARIES}; do
+        echo "#!/bin/sh" > ${D}${bindir}/$x
+        # Make the disabled script emit invalid parameters for those configure
+        # scripts which call it without checking the return code.
+        echo "echo '--should-not-have-used-$x'" >> ${D}${bindir}/$x
+        echo "exit 1" >> ${D}${bindir}/$x
+        chmod 755 ${D}${bindir}/$x
+    done
+}
+