libtiff: cmake: libtiffxx is static on win32

SDL Commits
1 
From 0e58c40f80de23c677c158f6f1f8655d45cbb911 Mon Sep 17 00:00:00 2001
From: Roger Leigh <[EMAIL REDACTED]>
Date: Sun, 29 May 2022 11:23:45 +0100
Subject: [PATCH] cmake: libtiffxx is static on win32

---
 libtiff/CMakeLists.txt | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/libtiff/CMakeLists.txt b/libtiff/CMakeLists.txt
index b6b31677..ae1e49f4 100755
--- a/libtiff/CMakeLists.txt
+++ b/libtiff/CMakeLists.txt
@@ -189,7 +189,13 @@ if(CXX_SUPPORT)
   set(tiffxx_HEADERS
           tiffio.hxx)
 
-  add_library(tiffxx ../placeholder.h)
+  # No .def file for this library.
+  if (WIN32)
+      add_library(tiffxx STATIC ../placeholder.h)
+  else()
+      add_library(tiffxx ../placeholder.h)
+  endif()
+
   target_sources(tiffxx PRIVATE
           ${tiffxx_HEADERS}
           tif_stream.cxx)