Revert "[cleanup] Remove three unused proxy runtime functions"

This reverts commit 90b39673.

Reason for revert: These functions are in use by d8-js.cc

Original change's description:
> [cleanup] Remove three unused proxy runtime functions
>
> R=​jgruber@chromium.org
>
> Bug: v8:9183
> Change-Id: I789295e5bbea682b2e46ccf5a55c69dc74f0ed72
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1617669
> Auto-Submit: Simon Zünd <szuend@chromium.org>
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#61632}

TBR=jgruber@chromium.org,szuend@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:9183, v8:10289
Change-Id: Ibd8566151f036efe73c869dcfd2cfee2a559489b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2083299Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66536}

src/debug/debug-evaluate.cc

@@ -265,6 +265,7 @@ bool IntrinsicHasNoSideEffect(Runtime::FunctionId id) {
   /* Type checks */                           \
   V(IsArray)                                  \
   V(IsFunction)                               \
+  V(IsJSProxy)                                \
   V(IsJSReceiver)                             \
   V(IsRegExp)                                 \
   V(IsSmi)                                    \

src/runtime/runtime-proxy.cc

@@ -15,6 +15,26 @@
 namespace v8 {
 namespace internal {
 
+RUNTIME_FUNCTION(Runtime_IsJSProxy) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(Object, obj, 0);
+  return isolate->heap()->ToBoolean(obj.IsJSProxy());
+}
+
+RUNTIME_FUNCTION(Runtime_JSProxyGetHandler) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(JSProxy, proxy, 0);
+  return proxy.handler();
+}
+
+RUNTIME_FUNCTION(Runtime_JSProxyGetTarget) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(1, args.length());
+  CONVERT_ARG_CHECKED(JSProxy, proxy, 0);
+  return proxy.target();
+}
 
 RUNTIME_FUNCTION(Runtime_GetPropertyWithReceiver) {
   HandleScope scope(isolate);

src/runtime/runtime.h

@@ -373,6 +373,9 @@ namespace internal {
   F(CheckProxyHasTrapResult, 2, 1)     \
   F(CheckProxyDeleteTrapResult, 2, 1)  \
   F(GetPropertyWithReceiver, 3, 1)     \
+  F(IsJSProxy, 1, 1)                   \
+  F(JSProxyGetHandler, 1, 1)           \
+  F(JSProxyGetTarget, 1, 1)            \
   F(SetPropertyWithReceiver, 4, 1)
 
 #define FOR_EACH_INTRINSIC_REGEXP(F, I)             \