Fix incorrect result for Base.invmod(<:Signed, <:Unsigned)

base/intfuncs.jl

@@ -286,7 +286,7 @@ function invmod(n::Integer, m::Integer)
     g, x, y = gcdx(n, m)
     g != 1 && throw(DomainError((n, m), LazyString("Greatest common divisor is ", g, ".")))
     # Note that m might be negative here.
-    if n isa Unsigned && hastypemax(typeof(n)) && x > typemax(n)>>1
+    if promote_type(typeof(n), typeof(m))<:Unsigned && hastypemax(typeof(n)) && x > typemax(n)>>1
         # x might have wrapped if it would have been negative
         # adding back m forces a correction
         x += m

test/intfuncs.jl

@@ -258,6 +258,10 @@ end
         @test invmod(T(3), T(124))::T == 83
     end
 
+    for T in (Int8, Int16, Int32, Int64, Int128)
+        @test invmod(T(3), unsigned(T)(124)) == 83
+    end
+
     for T in (Int8, UInt8)
         for x in typemin(T):typemax(T)
             for m in typemin(T):typemax(T)