patch 9.0.1411: accuracy of profiling is not optimal

Problem:    Accuracy of profiling is not optimal.
Solution:   Use CLOCK_MONOTONIC if possible. (Ernie Rael, closes #12129)
diff --git a/src/testdir/test_profile.vim b/src/testdir/test_profile.vim
index e427179..534cc76 100644
--- a/src/testdir/test_profile.vim
+++ b/src/testdir/test_profile.vim
@@ -6,8 +6,13 @@
 source shared.vim
 source screendump.vim
 
-let s:header = 'count  total (s)   self (s)'
-let s:header_func = 'count  total (s)   self (s)  function'
+if has('prof_nsec')
+  let s:header = 'count     total (s)      self (s)'
+  let s:header_func = 'count     total (s)      self (s)  function'
+else
+  let s:header = 'count  total (s)   self (s)'
+  let s:header_func = 'count  total (s)   self (s)  function'
+endif
 
 func Test_profile_func()
   call RunProfileFunc('func', 'let', 'let')