Compiler: Fix pre-compilation as separate package (#57650)

As spotted by @Keno in
#57530 (comment)

Author: topolarity

Compiler/src/Compiler.jl

@@ -193,23 +193,22 @@ end
 module IRShow end # relies on string and IO operations defined in Base
 baremodule TrimVerifier end # relies on IRShow, so define this afterwards
 
-function load_irshow!()
-    if isdefined(Base, :end_base_include)
-        # This code path is exclusively for Revise, which may want to re-run this
-        # after bootstrap.
-        Compilerdir = Base.dirname(Base.String(@__SOURCE_FILE__))
-        include(IRShow, Base.joinpath(Compilerdir, "ssair/show.jl"))
-        include(TrimVerifier, Base.joinpath(Compilerdir, "verifytrim.jl"))
-    else
+if isdefined(Base, :end_base_include)
+    # When this module is loaded as the standard library, include these files as usual
+    include(IRShow, "ssair/show.jl")
+    include(TrimVerifier, "verifytrim.jl")
+else
+    function load_irshow!()
+        Base.delete_method(Base.which(verify_typeinf_trim, (IO, Vector{Any}, Bool)),)
         include(IRShow, "ssair/show.jl")
         include(TrimVerifier, "verifytrim.jl")
     end
-end
-if !isdefined(Base, :end_base_include)
-    # During bootstrap, skip including this file and defer it to base/show.jl to include later
-else
-    # When this module is loaded as the standard library, include this file as usual
-    load_irshow!()
+    function verify_typeinf_trim(io::IO, codeinfos::Vector{Any}, onlywarn::Bool)
+        # stub implementation
+        msg = "--trim verifier not defined"
+        onlywarn ? println(io, msg) : error(msg)
+    end
+    # During bootstrap, skip including these files and defer to base/show.jl to include it later
 end
 
 end # baremodule Compiler

Compiler/src/typeinfer.jl

@@ -1380,7 +1380,6 @@ function typeinf_ext_toplevel(methods::Vector{Any}, worlds::Vector{UInt}, trim_m
     return codeinfos
 end
 
-verify_typeinf_trim(io::IO, codeinfos::Vector{Any}, onlywarn::Bool) = (msg = "--trim verifier not defined"; onlywarn ? println(io, msg) : error(msg))
 verify_typeinf_trim(codeinfos::Vector{Any}, onlywarn::Bool) = invokelatest(verify_typeinf_trim, stdout, codeinfos, onlywarn)
 
 function return_type(@nospecialize(f), t::DataType) # this method has a special tfunc

Compiler/src/verifytrim.jl

@@ -310,7 +310,6 @@ end
 # driver / verifier implemented by juliac-buildscript.jl for the purpose of extensibility.
 # For now, it is part of Base.Compiler, but executed with invokelatest so that packages
 # could provide hooks to change, customize, or tweak its behavior and heuristics.
-Base.delete_method(Base.which(verify_typeinf_trim, (IO, Vector{Any}, Bool)),)
 function verify_typeinf_trim(io::IO, codeinfos::Vector{Any}, onlywarn::Bool)
     errors, parents = get_verify_typeinf_trim(codeinfos)