patch 9.0.0402: javascript module files are not recoginzed

Problem:    Javascript module files are not recoginzed.
Solution:   Recognize "*.jsm" files as Javascript. (Brett Holman,
            closes #11069)

Author: holmanb

runtime/filetype.vim

@@ -940,7 +940,7 @@ au BufNewFile,BufRead *.java,*.jav		setf java
 au BufNewFile,BufRead *.jj,*.jjt		setf javacc
 
 " JavaScript, ECMAScript, ES module script, CommonJS script
-au BufNewFile,BufRead *.js,*.javascript,*.es,*.mjs,*.cjs   setf javascript
+au BufNewFile,BufRead *.js,*.jsm,*.javascript,*.es,*.mjs,*.cjs   setf javascript
 
 " JavaScript with React
 au BufNewFile,BufRead *.jsx			setf javascriptreact

src/testdir/test_filetype.vim

@@ -275,7 +275,7 @@ let s:filename_checks = {
     \ 'jam': ['file.jpl', 'file.jpr', 'JAM-file.file', 'JAM.file', 'Prl-file.file', 'Prl.file'],
     \ 'java': ['file.java', 'file.jav'],
     \ 'javacc': ['file.jj', 'file.jjt'],
-    \ 'javascript': ['file.js', 'file.javascript', 'file.es', 'file.mjs', 'file.cjs'],
+    \ 'javascript': ['file.js', 'file.jsm', 'file.javascript', 'file.es', 'file.mjs', 'file.cjs'],
     \ 'javascript.glimmer': ['file.gjs'],
     \ 'javascriptreact': ['file.jsx'],
     \ 'jess': ['file.clp'],

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    402,
 /**/
     401,
 /**/