Made most libraries panic on js targets instead of not compiling

core/dynlib/lib_js.odin

@@ -0,0 +1,15 @@
+//+build js
+//+private
+package dynlib
+
+_load_library :: proc(path: string, global_symbols := false) -> (Library, bool) {
+	panic("core:dynlib not supported by JS target")
+}
+
+_unload_library :: proc(library: Library) -> bool {
+	panic("core:dynlib not supported by JS target")
+}
+
+_symbol_address :: proc(library: Library, symbol: string) -> (ptr: rawptr, found: bool) {
+	panic("core:dynlib not supported by JS target")
+}