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We actually have the same behavior in @babel/plugin-transform-block-scoping.🤔

It seems we can remove transform-block-scoped-functions.

  "transform-block-scoped-functions": {
    "chrome": "41",
    "opera": "28",
    "edge": "12",
    "firefox": "46",
    "safari": "10",
    "node": "4",
    "deno": "1",
    "ie": "11",
    "ios": "10",
    "samsung": "3.4",
    "opera_mobile": "28",
    "electron": "0.21"
  },

  "transform-block-scoping": {
    "chrome": "50",
    "opera": "37",
    "edge": "14",
    "firefox": "53",
    "safari": "11",
    "node": "6",
    "deno": "1",
    "ios": "11",
    "samsung": "5",
    "opera_mobile": "37",
    "electron": "1.1"
  },

@liuxingbaoyu Yeah we could consider doing it for Babel 8, if transform-block-scoping covers all its tests.

It might be worth preparing a test262 CI for Babel 8. :)
Unfortunately transform-block-scoped-functions only had one test before that PR.
As I understand it, the difference between them is that transform-block-scoped-functions are not skipped in strict mode.
I just did some testing and this seems to make sense.

PS F:\git\babel-test262-runner\engine\node\bin> .\node.exe -v
v0.10.48
F:\git\babel-test262-runner\engine\node\bin\1.js:10
    function f() {
    ^^^^^^^^
SyntaxError: In strict mode code, functions can only be declared at top level or immediately within another function.
    at Module._compile (module.js:439:25)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:945:3

https://github.com/compat-table/compat-table/blob/1a1ccdc02b8b2158ab39a6146d8a7308f43c830b/data-es6.js#L14285

console.log(a());
function a() {
  "use strict";
  if (f() !== 1) return false;
  function f() {
    return 1;
  }
  {
    if (f() !== 2) return false;
    function f() {
      return 2;
    }
    if (f() !== 2) return false;
  }
  if (f() !== 1) return false;
  return true;
}

It seems good from the test262 results.

The three new failures are eval related, because transform-block-scoped-function used to transform regardless of whether it was in strict mode or not, but now it only transforms in strict mode.
And strict mode is not passed into the eval transformation.

Another failure is because transform-async-generator-functions is transformed in Program.enter, the previous over-transformation of all functions unexpectedly made it succeed, now we only transform async function or function *, it Failed.
This should be fine in the real world as it just reduces throwing a ReferenceError.

But the current test failing on node 6 is weird and I need to keep investigating.

This seems to be a feature we didn't cover, it happens on node 6 but not node 8.

babel/babel-test262-runner@2973657
Oh, we have passed strict mode, I should look into it.

Update: Just parsing options. :)

switch (0) {
  default:
    function x() {
      return _x.apply(this, arguments);
    }
}
x;
console.log("ok");

This succeeded on local node 6, which means that the CI failure may be caused by other reasons. (possibly older version of Jest)
In this case, it doesn't matter if we skip it on node 6.

This PR is probably not suitable for landing Babel 7, it's complex and risky.
New bugs may be introduced and there may be compatibility issues between the two plugin versions.

For example
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The behavior of transform-block-scoped-function was buggy, and we avoided this bug in transform-block-scoping. 😅

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Maybe it doesn't matter if we land on Babel 7.
Because it's broken in the default plugin order.
(Although I don't understand why there are no new test262 successes🤔)

Let's merge it before the next Babel 8 release?
(This PR has passed test262 CI before moving to Babel 8.)