add some compatibility shims for internal functions changed in 1.4 (#34289)

(cherry picked from commit c33298d)

Author: JeffBezanson

base/methodshow.jl

@@ -73,7 +73,8 @@ end
 
 const empty_sym = Symbol("")
 
-function kwarg_decl(m::Method)
+# NOTE: second argument is deprecated and is no longer used
+function kwarg_decl(m::Method, kwtype = nothing)
     mt = get_methodtable(m)
     if isdefined(mt, :kwsorter)
         kwtype = typeof(mt.kwsorter)

base/util.jl

@@ -238,6 +238,12 @@ end
 
 # total number of bytes allocated so far
 gc_bytes(b::Ref{Int64}) = ccall(:jl_gc_get_total_bytes, Cvoid, (Ptr{Int64},), b)
+# NOTE: gc_bytes() is deprecated
+function gc_bytes()
+    b = Ref{Int64}()
+    gc_bytes(b)
+    b[]
+end
 
 """
     @allocated