automake: Adjust shebang lines to remove interpreter path hardcode
If build host perl (and other tools) is old and we use some kind
of toolchain to provide recent perl/python/etc to the OE build
we still locked to use build host perl due to hardcoded shebang
lines in automake scripts.
Behaviour was observed with Enterprise Linux 6 and devtoolset
toolchain from SCL (Software Collections) used to provide recent
version of perl (not provided with default buildtools-tarball).
Pass /usr/bin/env perl in ac_cv_path_PERL configuration variables
for class-native and class-nativesdk. Use patch to automake to replace
-w option in shebang line with modern way to enable warnings on perl
(i.e. "use warnings").
Also add nativesdk-autoconf to RDEPENDS to bring runtime dependencies
inline with other targets.
Note that ac_cv_path_PERL must be valid perl interpreter path
since configure will check perl version and Flock implementation.
It is not possible currently to use nativeperl from native
sysroot because automake does not DEPENDS on perl-native (and
doing so fails due to circular dependencies). Only possible
solution is to overwrite shebangs with nativeperl somewhere at
do_install() and update RDEPENDS for class-native. Or add perl
symlinks to nativeperl in sysroot.
For now it seems good to use perl found by /usr/bin/env from
automake-native.
