FEXLinuxTests: Migrate FD test to Catch2

unittests/FEXLinuxTests/tests/fd/test_close_range.cpp

@@ -1,7 +1,9 @@
+#include <catch2/catch.hpp>
+
 #include <cstdint>
 #include <unistd.h>
 
-int main() {
+TEST_CASE("Close Range") {
   int fd_base = dup(STDOUT_FILENO);
   for (size_t i = 0; i < 15; ++i) {
     dup(fd_base);
@@ -12,6 +14,5 @@ int main() {
   ::syscall(SYS_close_range, fd_base + 1, ~0U, 0);
 
   // Ensure that fd_base itself wasn't closed in close_range
-  int Result = close(fd_base);
-  return Result;
+  CHECK(close(fd_base) == 0);
 }