Editorial: ProxyTarget is always a function object in GetFunctionRealm (#3496)

Author: kimjg1119

esmeta-ignore.json

@@ -5,7 +5,6 @@
   "CompareTypedArrayElements",
   "DoWait",
   "FunctionBody[0,0].EvaluateFunctionBody",
-  "GetFunctionRealm",
   "GetViewByteLength",
   "INTRINSICS.Atomics.notify",
   "MakeMatchIndicesIndexPairArray",

spec.html

@@ -6646,6 +6646,7 @@ <h1>
         1. If _obj_ is a Proxy exotic object, then
           1. Perform ? ValidateNonRevokedProxy(_obj_).
           1. Let _proxyTarget_ be _obj_.[[ProxyTarget]].
+          1. Assert: _proxyTarget_ is a function object.
           1. Return ? GetFunctionRealm(_proxyTarget_).
         1. [id="step-getfunctionrealm-default-return"] Return the current Realm Record.
       </emu-alg>