specialize show of : to make reshape trimmable (#59598)

I also noticed that the standard Base.show_type_name appears to be
trimmable so we don't need the override. We might still want it for code
size, but probably not a big deal.

(cherry picked from commit 12f7bb5)

Author: JeffBezanson

base/essentials.jl

@@ -1009,6 +1009,10 @@ struct Colon <: Function
 end
 const (:) = Colon()
 
+function show(io::IO, ::Colon)
+    show_type_name(io, Colon.name)
+    print(io, "()")
+end
 
 """
     Val(c)

contrib/juliac/juliac-trim-base.jl

@@ -77,7 +77,6 @@ end
             print(io, T.var.name)
         end
     end
-    show_type_name(io::IO, tn::Core.TypeName) = print(io, tn.name)
 
     mapreduce(f::F, op::F2, A::AbstractArrayOrBroadcasted; dims=:, init=_InitialValue()) where {F, F2} =
     _mapreduce_dim(f, op, init, A, dims)

test/trimming/trimmability.jl

@@ -50,5 +50,7 @@ function @main(args::Vector{String})::Cint
     catch
     end
 
+    Base.donotdelete(reshape([1,2,3],:,1,1))
+
     return 0
 end