support let (#4227)

test/compress/const.js

@@ -161,31 +161,6 @@ merge_vars_3: {
     expect_stdout: true
 }
 
-reduce_merge_vars: {
-    options = {
-        merge_vars: true,
-        reduce_vars: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        const a = console;
-        console.log(typeof a);
-        var b = typeof a;
-        console.log(b);
-    }
-    expect: {
-        var b = console;
-        console.log(typeof b);
-        b = typeof b;
-        console.log(b);
-    }
-    expect_stdout: [
-        "object",
-        "object",
-    ]
-}
-
 use_before_init_1: {
     options = {
         reduce_vars: true,
@@ -312,24 +287,6 @@ reduce_block_1: {
     expect_stdout: "object"
 }
 
-reduce_block_1_toplevel: {
-    options = {
-        reduce_vars: true,
-        toplevel: true,
-    }
-    input: {
-        {
-            const a = typeof console;
-            console.log(a);
-        }
-    }
-    expect: {
-        var a = typeof console;
-        console.log(a);
-    }
-    expect_stdout: "object"
-}
-
 reduce_block_2: {
     options = {
         reduce_vars: true,
@@ -373,7 +330,7 @@ reduce_block_2_toplevel: {
     expect_stdout: true
 }
 
-hoist_props_1: {
+hoist_props: {
     options = {
         hoist_props: true,
         reduce_vars: true,
@@ -397,28 +354,6 @@ hoist_props_1: {
     expect_stdout: "PASS"
 }
 
-hoist_props_2: {
-    options = {
-        hoist_props: true,
-        passes: 2,
-        reduce_vars: true,
-        toplevel: true,
-    }
-    input: {
-        {
-            const o = {
-                p: "PASS",
-            };
-            console.log(o.p);
-        }
-    }
-    expect: {
-        var o_p = "PASS";
-        console.log(o_p);
-    }
-    expect_stdout: "PASS"
-}
-
 loop_block_1: {
     options = {
         loops: true,
@@ -559,29 +494,6 @@ dead_block_after_return: {
     expect_stdout: true
 }
 
-const_to_var_scope_adjustment: {
-    options = {
-        conditionals: true,
-        inline: true,
-        reduce_vars: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        for (var k in [ 42 ])
-            console.log(function f() {
-                if (k) {
-                    const a = 0;
-                }
-            }());
-    }
-    expect: {
-        for (var k in [ 42 ])
-            console.log(void (k && 0));
-    }
-    expect_stdout: "undefined"
-}
-
 do_if_continue_1: {
     options = {
         if_return: true,
@@ -687,7 +599,7 @@ legacy_scope: {
     expect_stdout: true
 }
 
-issue_4191_1: {
+issue_4191: {
     options = {
         functions: true,
         reduce_vars: true,
@@ -708,24 +620,6 @@ issue_4191_1: {
     expect_stdout: true
 }
 
-issue_4191_2: {
-    options = {
-        functions: true,
-        reduce_vars: true,
-        toplevel: true,
-        unused: true,
-    }
-    input: {
-        const a = function() {};
-        console.log(typeof a, a());
-    }
-    expect: {
-        function a() {};
-        console.log(typeof a, a());
-    }
-    expect_stdout: "function undefined"
-}
-
 issue_4193: {
     options = {
         dead_code: true,