Handle integer bounds on left arguments in the environment

In subtyping proper, variables introduced on the left (i.e. forall
variables) don't have any equality constraints, because we have no
syntax for creating them. However, intersection does sometimes create
such environments, so we need to handle it in subtyping.

src/subtype.c

@@ -1048,15 +1048,17 @@ static int subtype_tuple(jl_datatype_t *xd, jl_datatype_t *yd, jl_stenv_t *e, in
     env.i = env.j = 0;
     env.vx = env.vy = 0;
     env.vvx = env.vvy = JL_VARARG_NONE;
-    if (env.lx > 0)
+    jl_varbinding_t *xbb = NULL;
+    if (env.lx > 0) {
         env.vvx = jl_vararg_kind(jl_tparam(env.xd, env.lx-1));
+        if (env.vvx == JL_VARARG_BOUND)
+            xbb = lookup(e, (jl_tvar_t *)jl_tparam1(jl_tparam(env.xd, env.lx - 1)));
+    }
     if (env.ly > 0)
         env.vvy = jl_vararg_kind(jl_tparam(env.yd, env.ly-1));
-    if (env.vvx != JL_VARARG_NONE && env.vvx != JL_VARARG_INT) {
-        jl_varbinding_t *bb = NULL;
-        if (env.vvx == JL_VARARG_BOUND)
-            bb = lookup(e, (jl_tvar_t*)jl_tparam1(jl_tparam(env.xd, env.lx-1)));
-        if (env.vvx == JL_VARARG_UNBOUND || (bb && !bb->right)) {
+    if (env.vvx != JL_VARARG_NONE && env.vvx != JL_VARARG_INT &&
+        (!xbb || !jl_is_long(xbb->lb))) {
+        if (env.vvx == JL_VARARG_UNBOUND || (xbb && !xbb->right)) {
             // Unbounded on the LHS, bounded on the RHS
             if (env.vvy == JL_VARARG_NONE || env.vvy == JL_VARARG_INT)
                 return 0;
@@ -1071,6 +1073,8 @@ static int subtype_tuple(jl_datatype_t *xd, jl_datatype_t *yd, jl_stenv_t *e, in
         size_t nx = env.lx;
         if (env.vvx == JL_VARARG_INT)
             nx += jl_vararg_length(jl_tparam(env.xd, env.lx-1)) - 1;
+        else if (xbb && jl_is_long(xbb->lb))
+            nx += jl_unbox_long(xbb->lb) - 1;
         else
             assert(env.vvx == JL_VARARG_NONE);
         size_t ny = env.ly;

test/subtype.jl

@@ -1584,3 +1584,7 @@ let T31805 = Tuple{Type{Tuple{}}, Tuple{Vararg{Int8, A}}} where A,
     S31805 = Tuple{Type{Tuple{Vararg{Int32, A}}}, Tuple{Vararg{Int16, A}}} where A
     @test !issub(T31805, S31805)
 end
+@testintersect(
+    Tuple{Array{Tuple{Vararg{Int64,N}},N},Tuple{Vararg{Array{Int64,1},N}}} where N,
+    Tuple{Array{Tuple{Int64},1}, Tuple},
+    Tuple{Array{Tuple{Int64},1},Tuple{Array{Int64,1}}})