[llvm] [flang-rt] Fix for TIMEF test case hanging on Windows (PR #195651)

[Eugene Epshteyn via llvm-commits]

================
@@ -41,8 +41,11 @@ TEST(TimeIntrinsics, Timef) {
   // Loop until we get a different value from Timef. If we don't get one
   // before we time out, then we should probably look into an implementation
   // for Timef with a better timer resolution.
-  // By default, this loop should burn for 1 second.
-  for (end = start; end == start; end = RTNAME(Timef)()) {
+  // By default, this loop should burn for 1 second or until the end of
----------------
eugeneepshteyn wrote:

Can't really claim 1 second, since depends on CPU capabilities

https://github.com/llvm/llvm-project/pull/195651