patch 9.1.0906: filetype: Nvidia PTX files are not recognized

Problem:  filetype: Nvidia PTX files are not recognized
Solution: detect '*.ptx' files as ptx filetype (Yinzuo Jiang)

Reference: https://docs.nvidia.com/cuda/parallel-thread-execution/

closes: #16171

Signed-off-by: Yinzuo Jiang <jiangyinzuo@foxmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index ef1d8b5..2dc0f49 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -608,6 +608,7 @@
     ps1xml: ['file.ps1xml'],
     psf: ['file.psf'],
     psl: ['file.psl'],
+    ptx: ['file.ptx'],
     pug: ['file.pug'],
     puppet: ['file.pp'],
     purescript: ['file.purs'],
diff --git a/src/version.c b/src/version.c
index 4cf6862..c230d4f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    906,
+/**/
     905,
 /**/
     904,