inlining: fix the joint_effects calculation (#50117)

There are cases when `joint_effects` already has `:nothrow` tainted while the matches are
fully covered.

base/compiler/abstractinterpretation.jl

@@ -2441,11 +2441,9 @@ function abstract_eval_globalref(interp::AbstractInterpreter, g::GlobalRef, fram
     nothrow = false
     if isa(rt, Const)
         consistent = ALWAYS_TRUE
+        nothrow = true
         if is_mutation_free_argtype(rt)
             inaccessiblememonly = ALWAYS_TRUE
-            nothrow = true
-        else
-            nothrow = true
         end
     elseif isdefined_globalref(g)
         nothrow = true

base/compiler/ssair/inlining.jl

@@ -1401,7 +1401,7 @@ function compute_inlining_cases(@nospecialize(info::CallInfo), flag::UInt8, sig:
         fully_covered &= split_fully_covered
     end
 
-    joint_effects = Effects(joint_effects; nothrow=fully_covered)
+    fully_covered || (joint_effects = Effects(joint_effects; nothrow=false))
 
     if handled_all_cases && revisit_idx !== nothing
         # we handled everything except one match with unmatched sparams,

test/compiler/irutils.jl

@@ -1,9 +1,13 @@
 import Core: CodeInfo, ReturnNode, MethodInstance
 import Core.Compiler: IRCode, IncrementalCompact, argextype, singleton_type
 import Base.Meta: isexpr
+using InteractiveUtils: gen_call_with_extracted_types_and_kwargs
 
 argextype(@nospecialize args...) = argextype(args..., Any[])
 code_typed1(args...; kwargs...) = first(only(code_typed(args...; kwargs...)))::CodeInfo
+macro code_typed1(ex0...)
+    return gen_call_with_extracted_types_and_kwargs(__module__, :code_typed1, ex0)
+end
 get_code(args...; kwargs...) = code_typed1(args...; kwargs...).code
 
 # check if `x` is a statement with a given `head`