Fix getfield_tfunc when order or boundscheck is Vararg

Even if T has no intersection with the type we want, we don't know that we will
throw, because the arguments are optional.

Fixes #57292.

Author: xal-0

Compiler/src/tfuncs.jl

@@ -1073,17 +1073,15 @@ end
 end
 
 @nospecs function getfield_tfunc(𝕃::AbstractLattice, s00, name, boundscheck_or_order)
-    t = isvarargtype(boundscheck_or_order) ? unwrapva(boundscheck_or_order) :
-        widenconst(boundscheck_or_order)
-    hasintersect(t, Symbol) || hasintersect(t, Bool) || return Bottom
+    if !isvarargtype(boundscheck_or_order)
+        t = widenconst(boundscheck_or_order)
+        hasintersect(t, Symbol) || hasintersect(t, Bool) || return Bottom
+    end
     return getfield_tfunc(𝕃, s00, name)
 end
 @nospecs function getfield_tfunc(𝕃::AbstractLattice, s00, name, order, boundscheck)
     hasintersect(widenconst(order), Symbol) || return Bottom
-    if isvarargtype(boundscheck)
-        t = unwrapva(boundscheck)
-        hasintersect(t, Symbol) || hasintersect(t, Bool) || return Bottom
-    else
+    if !isvarargtype(boundscheck)
         hasintersect(widenconst(boundscheck), Bool) || return Bottom
     end
     return getfield_tfunc(𝕃, s00, name)

Compiler/test/inference.jl

@@ -6188,3 +6188,9 @@ end == Union{Float64,DomainError}
 @test Compiler.argtypes_to_type(Any[ Int, UnitRange{Int}, Vararg{Pair{Any, Union{}}}, Float64 ]) === Tuple{Int, UnitRange{Int}, Float64}
 @test Compiler.argtypes_to_type(Any[ Int, UnitRange{Int}, Vararg{Pair{Any, Union{}}}, Float64, Memory{2} ]) === Union{}
 @test Base.return_types(Tuple{Tuple{Int, Vararg{Pair{Any, Union{}}}}},) do x; Returns(true)(x...); end |> only === Bool
+
+# issue #57292
+f57292(xs::Union{Tuple{String}, Int}...) = getfield(xs...)
+g57292(xs::String...) = getfield(("abc",), 1, :not_atomic, xs...)
+@test Base.infer_return_type(f57292) == String
+@test Base.infer_return_type(g57292) == String