build-package.sh: use globstar when splitting static libraries

Handle cases when static libraries located in subdirectory.

Enables support for globstar (example './**/*.a') pattern in subpackage
splitting.

scripts/build/termux_create_subpackages.sh

@@ -3,7 +3,7 @@ termux_create_subpackages() {
 	if [[ -n $(shopt -s nullglob; echo lib/*.a) ]] && [ -z "${TERMUX_PKG_NO_STATICSPLIT}" ]; then
 		# Add virtual -static sub package if there are include files:
 		local _STATIC_SUBPACKAGE_FILE=$TERMUX_PKG_TMPDIR/${TERMUX_PKG_NAME}-static.subpackage.sh
-		echo TERMUX_SUBPKG_INCLUDE=\"lib/*.a lib/*.la\" > "$_STATIC_SUBPACKAGE_FILE"
+		echo TERMUX_SUBPKG_INCLUDE=\"lib/**/*.a lib/**/*.la\" > "$_STATIC_SUBPACKAGE_FILE"
 		echo "TERMUX_SUBPKG_DESCRIPTION=\"Static libraries for ${TERMUX_PKG_NAME}\"" >> "$_STATIC_SUBPACKAGE_FILE"
 	fi
 
@@ -30,16 +30,20 @@ termux_create_subpackages() {
 		# shellcheck source=/dev/null
 		source "$subpackage"
 
+		# Allow globstar (i.e. './**/') patterns.
+		shopt -s globstar
 		for includeset in $TERMUX_SUBPKG_INCLUDE; do
 			local _INCLUDE_DIRSET
 			_INCLUDE_DIRSET=$(dirname "$includeset")
 			test "$_INCLUDE_DIRSET" = "." && _INCLUDE_DIRSET=""
+
 			if [ -e "$includeset" ] || [ -L "$includeset" ]; then
 				# Add the -L clause to handle relative symbolic links:
 				mkdir -p "$SUB_PKG_MASSAGE_DIR/$_INCLUDE_DIRSET"
 				mv "$includeset" "$SUB_PKG_MASSAGE_DIR/$_INCLUDE_DIRSET"
 			fi
 		done
+		shopt -u globstar
 
 		local SUB_PKG_ARCH=$TERMUX_ARCH
 		test -n "$TERMUX_SUBPKG_PLATFORM_INDEPENDENT" && SUB_PKG_ARCH=all