wasi: support nanosec precision in monotonic clock on Windows (#1123)

Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>

internal/platform/time_windows.go

@@ -0,0 +1,27 @@
+//go:build windows
+
+package platform
+
+import (
+	"unsafe"
+)
+
+var qpc = kernel32.NewProc("QueryPerformanceCounter")
+
+// On Windows, time.Time handled in time package cannot have the nanosecond precision.
+// The reason is that by default, it doesn't use QueryPerformanceCounter[1], but instead, use "interrupt time"
+// which doesn't support nanoseconds precision (though it is a monotonic) [2, 3, 4, 5].
+//
+// [1] https://learn.microsoft.com/en-us/windows/win32/api/profileapi/nf-profileapi-queryperformancecounter
+// [2] https://github.com/golang/go/blob/0cd309e12818f988693bf8e4d9f1453331dcf9f2/src/runtime/sys_windows_amd64.s#L297-L298
+// [3] https://github.com/golang/go/blob/0cd309e12818f988693bf8e4d9f1453331dcf9f2/src/runtime/os_windows.go#L549-L551
+// [4] https://github.com/golang/go/blob/master/src/runtime/time_windows.h#L7-L13
+// [5] http://web.archive.org/web/20210411000829/https://wrkhpi.wordpress.com/2007/08/09/getting-os-information-the-kuser_shared_data-structure/
+//
+// Therefore, on Windows, we directly invoke the syscall for QPC instead of time.Now or runtime.nanotime.
+// See https://github.com/golang/go/issues/31160 for example.
+func nanotime() int64 {
+	var now int64
+	_, _, _ = qpc.Call(uintptr(unsafe.Pointer(&now)))
+	return now
+}