gen: output bit32 ops even for invalid variables

Do not short-circuit the 5.1 adaptation of the output code
when an invalid type is detected. (That patching of the AST
shouldn't really be at the type checking stage...)

Fixes #673.

spec/cli/gen_spec.lua

@@ -197,6 +197,26 @@ describe("tl gen", function()
             local y = bit32.lshift(2, 3)
          ]], util.read_file(lua_name))
       end)
+
+      it("generates bit32 operations even for invalid variables (regression test for #673)", function()
+         local name = util.write_tmp_file(finally, [[
+
+            local foo = require("nonexisting")
+            local y = 2 | (foo.wat << 9)
+            local x = ~y
+         ]])
+         local pd = io.popen(util.tl_cmd("gen", "--gen-target=5.1", name), "r")
+         local output = pd:read("*a")
+         util.assert_popen_close(0, pd:close())
+         local lua_name = tl_to_lua(name)
+         assert.match("Wrote: " .. lua_name, output, 1, true)
+         util.assert_line_by_line([[
+            local bit32 = bit32; if not bit32 then local p, m = pcall(require, 'bit32'); if p then bit32 = m end end
+            local foo = require("nonexisting")
+            local y = bit32.bor(2, (bit32.lshift(foo.wat, 9)))
+            local x = bit32.bnot(y)
+         ]], util.read_file(lua_name))
+      end)
    end)
 
    describe("with --gen-target=5.3", function()

tl.lua

@@ -9986,14 +9986,14 @@ tl.type_check = function(ast, opts)
                if not node.type then
                   node.type, meta_on_operator = check_metamethod(node, node.op.op, a)
                   if not node.type then
-                     return node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' on type %s", resolve_tuple(orig_a))
+                     node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' on type %s", resolve_tuple(orig_a))
                   end
                end
                if a.typename == "map" then
                   if a.keys.typename == "number" or a.keys.typename == "integer" then
                      node_warning("hint", node, "using the '#' operator on a map with numeric key type may produce unexpected results")
                   else
-                     return node_error(node, "using the '#' operator on this map will always return 0")
+                     node_error(node, "using the '#' operator on this map will always return 0")
                   end
                end
 
@@ -10032,7 +10032,7 @@ tl.type_check = function(ast, opts)
                if not node.type then
                   node.type, meta_on_operator = check_metamethod(node, node.op.op, a, b)
                   if not node.type then
-                     return node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' for types %s and %s", resolve_tuple(orig_a), resolve_tuple(orig_b))
+                     node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' for types %s and %s", resolve_tuple(orig_a), resolve_tuple(orig_b))
                   end
                end
 

tl.tl

@@ -9986,14 +9986,14 @@ tl.type_check = function(ast: Node, opts: TypeCheckOptions): Result, string
                if not node.type then
                   node.type, meta_on_operator = check_metamethod(node, node.op.op, a)
                   if not node.type then
-                     return node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' on type %s", resolve_tuple(orig_a))
+                     node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' on type %s", resolve_tuple(orig_a))
                   end
                end
                if a.typename == "map" then
                   if a.keys.typename == "number" or a.keys.typename == "integer" then
                       node_warning("hint", node, "using the '#' operator on a map with numeric key type may produce unexpected results")
                   else
-                      return node_error(node, "using the '#' operator on this map will always return 0")
+                      node_error(node, "using the '#' operator on this map will always return 0")
                   end
                end
 
@@ -10032,7 +10032,7 @@ tl.type_check = function(ast: Node, opts: TypeCheckOptions): Result, string
                if not node.type then
                   node.type, meta_on_operator = check_metamethod(node, node.op.op, a, b)
                   if not node.type then
-                     return node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' for types %s and %s", resolve_tuple(orig_a), resolve_tuple(orig_b))
+                     node_error(node, "cannot use operator '" .. node.op.op:gsub("%%", "%%%%") .. "' for types %s and %s", resolve_tuple(orig_a), resolve_tuple(orig_b))
                   end
                end