Implement mch_delay on top of libuv

Needed to temporarily move two static variables from os_unix.c to 'globals.h'
as those are shared by other functions still in os_unix.

src/os/time.c

@@ -0,0 +1,58 @@
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <uv.h>
+
+#include "vim.h"
+#include "term.h"
+
+static uv_mutex_t delay_mutex;
+static uv_cond_t delay_cond;
+
+static void delay(uint64_t ms);
+
+void time_init()
+{
+  uv_mutex_init(&delay_mutex);
+  uv_cond_init(&delay_cond);
+}
+
+void mch_delay(uint64_t ms, bool ignoreinput)
+{
+  int old_tmode;
+
+  if (ignoreinput) {
+    /* Go to cooked mode without echo, to allow SIGINT interrupting us
+     * here.  But we don't want QUIT to kill us (CTRL-\ used in a
+     * shell may produce SIGQUIT). */
+    in_mch_delay = true;
+    old_tmode = curr_tmode;
+
+    if (curr_tmode == TMODE_RAW)
+      settmode(TMODE_SLEEP);
+
+    delay(ms);
+
+    settmode(old_tmode);
+    in_mch_delay = false;
+  } else {
+    delay(ms);
+  }
+}
+
+static void delay(uint64_t ms)
+{
+  uint64_t hrtime;
+  int64_t ns = ms * 1000000; /* convert to nanoseconds */
+
+  uv_mutex_lock(&delay_mutex);
+
+  while (ns > 0) {
+    hrtime =  uv_hrtime();
+    if (uv_cond_timedwait(&delay_cond, &delay_mutex, ns) == UV_ETIMEDOUT)
+      break;
+    ns -= uv_hrtime() - hrtime;
+  }
+
+  uv_mutex_unlock(&delay_mutex);
+}