add the ability to specify the external name of a ccallable (JuliaLang#57763)

This will allow exporting julia `main` as something else so a separate
native `main` can be written to handle initialization. I'm sure it will
have lots of other uses too though.

Author: JeffBezanson

src/typeinfer.jl

@@ -1371,8 +1371,7 @@ function typeinf_ext_toplevel(methods::Vector{Any}, worlds::Vector{UInt}, trim_m
                 end
                 # additionally enqueue the ccallable entrypoint / adapter, which implicitly
                 # invokes the above ci
-                push!(codeinfos, rt)
-                push!(codeinfos, sig)
+                push!(codeinfos, item)
             end
         end
         while !isempty(tocompile)

src/verifytrim.jl

@@ -256,7 +256,7 @@ function get_verify_typeinf_trim(codeinfos::Vector{Any})
     caches = IdDict{MethodInstance,CodeInstance}()
     errors = ErrorList()
     parents = ParentMap()
-    for i = 1:2:length(codeinfos)
+    for i = 1:length(codeinfos)
         item = codeinfos[i]
         if item isa CodeInstance
             push!(inspected, item)
@@ -268,14 +268,14 @@ function get_verify_typeinf_trim(codeinfos::Vector{Any})
             end
         end
     end
-    for i = 1:2:length(codeinfos)
+    for i = 1:length(codeinfos)
         item = codeinfos[i]
         if item isa CodeInstance
             src = codeinfos[i + 1]::CodeInfo
             verify_codeinstance!(item, src, inspected, caches, parents, errors)
-        else
-            rt = item::Type
-            sig = codeinfos[i + 1]::Type
+        elseif item isa SimpleVector
+            rt = item[1]::Type
+            sig = item[2]::Type
             ptr = ccall(:jl_get_specialization1,
                         #= MethodInstance =# Ptr{Cvoid}, (Any, Csize_t, Cint),
                         sig, this_world, #= mt_cache =# 0)

test/verifytrim.jl

@@ -44,8 +44,8 @@ let infos = typeinf_ext_toplevel(Any[Core.svec(Base.SecretBuffer, Tuple{Type{Bas
 
             $""", repr)
 
-    resize!(infos, 2)
-    @test infos[1] isa Type && infos[2] isa Type
+    resize!(infos, 1)
+    @test infos[1] isa Core.SimpleVector && infos[1][1] isa Type && infos[1][2] isa Type
     errors, parents = get_verify_typeinf_trim(infos)
     desc = only(errors)
     @test !desc.first