Give vrt_ctx a "double now" timestamp for use in VCL/VRT/VMODs

Conflicts:
	bin/varnishd/cache/cache_vcl.c
	include/vrt.h

bin/varnishd/cache/cache_vcl.c

@@ -42,6 +42,7 @@
 #include "vrt.h"
 #include "vcli.h"
 #include "vcli_priv.h"
+#include "vtim.h"
 
 struct vcls {
 	unsigned		magic;
@@ -436,6 +437,7 @@ vcl_call_method(struct worker *wrk, struct req *req, struct busyobj *bo,
 		ctx.req = req;
 		if (req->obj)
 			ctx.http_obj = req->obj->http;
+		ctx.now = req->t_prev;
 	}
 	if (bo != NULL) {
 		// AZ(req);
@@ -446,7 +448,10 @@ vcl_call_method(struct worker *wrk, struct req *req, struct busyobj *bo,
 		ctx.http_bereq = bo->bereq;
 		ctx.http_beresp = bo->beresp;
 		ctx.bo = bo;
+		ctx.now = bo->t_prev;
 	}
+	if (ctx.now == 0)
+		ctx.now = VTIM_real();
 	ctx.ws = ws;
 	ctx.method = method;
 	ctx.handling = &wrk->handling;

include/vrt.h

@@ -102,6 +102,7 @@ struct vrt_ctx {
 	struct http			*http_bereq;
 	struct http			*http_beresp;
 
+	double				now;
 };
 
 /***********************************************************************/