msvc: check exit code

compiler/msvc.v

@@ -408,10 +408,13 @@ pub fn (v mut V) cc_msvc() {
 
 	// println('$cmd')
 
-	_ := os.exec(cmd) or {
+	res := os.exec(cmd) or {
 		println(err)
 		panic('msvc error')
 	}
+	if res.exit_code != 0 {
+		panic(res.output)
+	}
 	// println(res)
 	// println('C OUTPUT:')
 

vlib/time/time.v

@@ -11,9 +11,9 @@ const (
 )
 
 #include <time.h>
-#include <unistd.h> // sleep
 
 $if !windows {
+#include <unistd.h> // sleep	
 #include <sys/time.h>
 //#include <sys/wait.h>
 /// ^^^^ including this makes the windows build fail.