Record the defining symbol for lambda functions, too

Record the defining symbol for lambda functions, too

Also record it for the trampolines for primitives.

* lisp/emacs-lisp/comp.el (comp-spill-lap-function/symbol)
(comp-intern-func-in-ctxt): Use as source the defining symbol
embedded in the byte-code.
(comp-trampoline-compile): Use subr-name as the defining symbol
for the constructed lambda form.