feat: implement baremetal GC

fix: pthread gc

fix: xiao-esp32c3 symbol

refactor: use clite memset instead of linking

fix: stack top symbol

runtime/internal/lib/runtime/runtime_gc.go

@@ -1,4 +1,4 @@
-//go:build !nogc
+//go:build !nogc && !baremetal
 
 package runtime