[win] Fix some bitrot for building

Needed an option to disable LTO, and a couple of errors that crept in
with preprocessor and vulkan improvements.

config.d/compiling.m4

@@ -132,6 +132,12 @@ AC_ARG_ENABLE(optimize,
 	optimize=yes
 )
 
+AC_ARG_ENABLE(lto,
+	AS_HELP_STRING([--disable-lto], [disable link-time optimizations]),
+	use_lto=$enable_lto,
+	use_lto=yes
+)
+
 if test "x$host_cpu" = xaarch64; then
 	simd=neon
 else
@@ -172,7 +178,9 @@ AC_MSG_CHECKING(for optimization)
 if test "x$optimize" = xyes -a "x$leave_cflags_alone" != "xyes"; then
 	AC_MSG_RESULT(yes)
 	BUILD_TYPE="$BUILD_TYPE Optimize"
+	if test "x$use_lto" = xyes; then
 		QF_CC_OPTION(-flto=auto)
+	fi
 	if test "x$GCC" = xyes; then
 		saved_cflags="$CFLAGS"
 		dnl CFLAGS=""

libs/video/targets/vid_win_vulkan.c

@@ -176,7 +176,11 @@ win_vulkan_create_surface (vulkan_ctx_t *ctx)
 static void
 delete_vulkan_context (vulkan_ctx_t *ctx)
 {
+	if (ctx->presentation) {
+		free (ctx->presentation);
+	}
 	va_destroy_context (ctx->va_ctx);
+	free (ctx);
 }
 
 vulkan_ctx_t *
@@ -184,6 +188,7 @@ Win_Vulkan_Context (vid_internal_t *vi)
 {
 	vulkan_ctx_t *ctx = calloc (1, sizeof (vulkan_ctx_t));
 	*ctx = (vulkan_ctx_t) {
+		.delete = delete_vulkan_context,
 		.load_vulkan = load_vulkan_library,
 		.unload_vulkan = unload_vulkan_library,
 		.get_presentation_support = win_vulkan_get_presentation_support,

tools/cross/mingw64/cross-configure.sh

@@ -20,4 +20,5 @@ export QCSYSPREFIX=$MINGW_USR
 	--enable-silent-rules \
 	--host=x86_64-w64-mingw32.static \
 	--disable-shared \
+	--disable-lto \
 	$*

tools/qfcc/source/cpp.c

@@ -576,7 +576,7 @@ run_cpp (const char *filename, const char *ext)
 	}
 
 #ifdef _WIN32
-	if (!options.save_temps && !options.preprocess_only)
+	if (!options.save_temps && !options.preprocess_only) {
 		mktemp (tempname->str);
 	}