tigervnc: fix build issues

%ci:no-build

x11-packages/tigervnc/build.sh

@@ -40,6 +40,8 @@ termux_step_pre_configure() {
 	export ACLOCAL="aclocal -I ${TERMUX_PREFIX}/share/aclocal"
 	autoreconf -fi
 
+	patch -p3 -i ${TERMUX_PKG_BUILDER_DIR}/fix-xorg-configure.patch.txt
+
 	CFLAGS="${CFLAGS/-Os/-Oz} -DFNDELAY=O_NDELAY -DINITARGS=void"
 	CPPFLAGS="${CPPFLAGS} -I${TERMUX_PREFIX}/include/libdrm"
 	LDFLAGS="${LDFLAGS} -llog"

x11-packages/tigervnc/fix-xorg-configure.patch.txt

@@ -0,0 +1,20 @@
+--- ./unix/xserver/configure.bak	2021-03-01 20:05:50.721308293 +0000
++++ ./unix/xserver/configure	2021-03-01 20:06:31.217671971 +0000
+@@ -25631,7 +25631,7 @@
+   RAWCPP="$ac_cv_path_RAWCPP"
+ fi
+ 
+-
++if false; then
+ # Check for flag to avoid builtin definitions - assumes unix is predefined,
+ # which is not the best choice for supporting other OS'es, but covers most
+ # of the ones we need for now.
+@@ -25680,7 +25680,7 @@
+ 	fi
+ fi
+ rm -f conftest.$ac_ext
+-
++fi
+ 
+ 
+