postgresql, revbump for libxml2, fix build for riscv64 (#12859)

dev-db/postgresql/postgresql12-12.0.recipe

@@ -20,7 +20,7 @@ you want to build, and let PostgreSQL safely and robustly store your data."
 HOMEPAGE="https://www.postgresql.org/"
 COPYRIGHT="1996-2019 PostgreSQL Global Development Group"
 LICENSE="PostgreSQL"
-REVISION="7"
+REVISION="8"
 SOURCE_URI="http://ftp.postgresql.org/pub/source/v$portVersion/postgresql-$portVersion.tar.bz2"
 CHECKSUM_SHA256="cda2397215f758b793f741c86be05468257b0e6bcb1a6113882ab5d0df0855c6"
 SOURCE_DIR="postgresql-$portVersion"
@@ -162,6 +162,10 @@ BUILD_PREREQUIRES="
 	cmd:touch
 	"
 
+if [ "$targetArchitecture" = riscv64 ]; then
+	spinlocks="--disable-spinlocks"
+fi
+
 BUILD()
 {
 	libtoolize --force --copy --install
@@ -177,7 +181,8 @@ BUILD()
 		--with-openssl \
 		--with-pam \
 		--with-template=haiku \
-		--disable-thread-safety
+		--disable-thread-safety \
+		$spinlocks
 	make $jobArgs
 }