toolchain-scripts: preserve host path in environment setup script
The environment setup script generated in the build directory sets the PATH
variable by expanding ${PATH} which would have host paths filtered. Sourcing
this script to run runqemu will not work as it complains host stty (/bin/stty)
cannot be found.
To resolve this, the script no longer expands ${PATH} during generation time,
instead it will now source oe-init-build-env to initialize the build
environment so that all host paths will be preserved. Also be sure to prepend
STAGING_BINDIR_TOOLCHAIN to the PATH variable so that the toolchain from the
build directory can be found.
[YOCTO #12695]
Signed-off-by: Chin Huat Ang <chin.huat.ang@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
