winpthreads: add a .gitignore

This helps when vendoring winpthreads as a subtree.

Signed-off-by: LIU Hao <lh_mouse@126.com>

mingw-w64-libraries/winpthreads/.gitignore

diff --git a/mingw-w64-libraries/winpthreads/.gitignore b/mingw-w64-libraries/winpthreads/.gitignore
new file mode 100644
index 0000000..3d10223
--- /dev/null
+++ b/mingw-w64-libraries/winpthreads/.gitignore
@@ -0,0 +1,41 @@
+# Temporary files
+*~
+.*
+
+# Compiled files
+*.o
+*.a
+*.so
+*.out
+*.exe
+*.dll
+*.lo
+*.la
+*.gch
+*.obj
+*.res
+
+# Specialized files
+autom4te.cache
+config.cache
+Makefile
+libtool
+config.status
+config.h
+confdefs.h
+stamp-h1
+
+# Autotools test results
+*.trs
+*.test
+*.test.exe
+*.log
+
+# Merge conflict files
+*.orig
+*.rej
+
+# Others
+*.swp
+*.tar
+*.tar.*