Bug 1782569 - Add ErrorContext member to SharedContext r=nbp

We will use it with ReportOutOfMemory() calls and probably other places.

Specifically: FunctionBox::setAsmJSModule() calls ReportOutOfMemory().

Differential Revision: https://phabricator.services.mozilla.com/D153966

js/src/shell/js.cpp

@@ -5408,7 +5408,7 @@ static bool DumpAST(JSContext* cx, const JS::ReadOnlyCompileOptions& options,
     ModuleBuilder builder(cx, &parser);
 
     SourceExtent extent = SourceExtent::makeGlobalExtent(length);
-    ModuleSharedContext modulesc(cx, options, builder, extent);
+    ModuleSharedContext modulesc(cx, &ec, options, builder, extent);
     pn = parser.moduleBody(&modulesc);
   }