perl-ptest: copy xconfig data from perl source directory

The following perl ptests:

  - dist/ExtUtils-ParseXS/t/001-basic
  - dist/ExtUtils-ParseXS/t/002-more
  - dist/ExtUtils-ParseXS/t/003-usage
  - cpan/ExtUtils-Constant/t/Constant
  - cpan/ExtUtils-MakeMaker/t/02-xsdynamic

are erroring out with:
| /usr/lib/perl/ptest/perl_langinfo.h:8:10: fatal error:
xconfig.h: No such file or directory
|     8 | #include "xconfig.h"

xconfig.h contains references to the build host architecture and was
removed by commit 2e0f30c ("perl: do not install files that contain
build host specific data")

However, it is still included from various other places including these
tests, and we are still depending on build host architecture data by
including the patches from perl-cross recipe, a dependency to perl recipe.

xconfig.h was added back as a copy step in the commit f90922c
("update 5.36.1 -> 5.38.0") but was not added back in perl-ptest include
file.

Borrowed the logic from the above commit to make a copy of config.h
that is specific to the target architecture. The changes in this commit
fixes the test failures.
   
Signed-off-by: Rajendra Desai <rajendra.desai@emerson.com>

Author: rajendra-desai-ni

meta/recipes-devtools/perl/perl-ptest.inc

@@ -45,6 +45,11 @@ do_install_ptest () {
 
 	 # Remove files with host-specific configuration for building native binaries
 	 rm ${D}${PTEST_PATH}/Makefile.config ${D}${PTEST_PATH}/xconfig.h ${D}${PTEST_PATH}/xconfig.sh
+
+	 # xconfig.h contains references to build host architecture, and yet is included from various other places.
+	 # To make it reproducible let's make it a copy of config.h patch that is specific to the target architecture.
+	 # It is believed that the original header is the product of building miniperl (a helper executable built with host compiler).
+	 cp ${D}${libdir}/perl5/${PV}/${TARGET_ARCH}-linux/CORE/config.h ${D}${PTEST_PATH}/xconfig.h
 }
 
 python populate_packages:prepend() {