patch 9.1.1073: tests: test_compiler fails on Windows without Maven

Problem:  tests: test_compiler fails on Windows without Maven.
Solution: Add Xspotbugs directory to $PATH when mvn is not available
          (zeertzjq).

closes: #16576

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/testdir/test_compiler.vim

@@ -417,8 +417,10 @@ func Test_compiler_spotbugs_properties()
 
   " TEST INTEGRATION WITH A SUPPORTED COMPILER PLUGIN.
   if filereadable($VIMRUNTIME .. '/compiler/maven.vim')
+    let save_PATH = $PATH
     if !executable('mvn')
       if has('win32')
+        let $PATH = 'Xspotbugs;' .. $PATH
         " This is what ":help executable()" suggests.
         call writefile([], 'Xspotbugs/mvn.cmd')
       else
@@ -702,6 +704,7 @@ func Test_compiler_spotbugs_properties()
 
     bwipeout
     setlocal makeprg=
+    let $PATH = save_PATH
   endif
 
   filetype plugin off

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1073,
 /**/
     1072,
 /**/