fix crash when converting symbol or BigInt to dynamic

Summary:
Throws a JS error instead of crashing Hermes with an invariant when trying to convert a JS symbol or BigInt to a folly::dynamic value.

Changelog:
[General][Fixed] - Fixed crash when converting JS symbol to folly::dynamic

Reviewed By: javache

Differential Revision: D40444164

fbshipit-source-id: 37df8059b2eb425563f30cf1e9c0436e8d665b34

ReactCommon/jsi/jsi/JSIDynamic.cpp

@@ -129,8 +129,7 @@ void dynamicFromValueShallow(
     output = value.getNumber();
   } else if (value.isString()) {
     output = value.getString(runtime).utf8(runtime);
-  } else {
-    CHECK(value.isObject());
+  } else if (value.isObject()) {
     Object obj = value.getObject(runtime);
     if (obj.isArray(runtime)) {
       output = folly::dynamic::array();
@@ -140,6 +139,12 @@ void dynamicFromValueShallow(
       output = folly::dynamic::object();
     }
     stack.emplace_back(&output, std::move(obj));
+  } else if (value.isBigInt()) {
+    throw JSError(runtime, "JS BigInts are not convertible to dynamic");
+  } else if (value.isSymbol()) {
+    throw JSError(runtime, "JS Symbols are not convertible to dynamic");
+  } else {
+    throw JSError(runtime, "Value is not convertible to dynamic");
   }
 }