perf: improve isFileReadable performance

[Demivan]

Description

accessSync used in isFileReadable is slow because it throws and Node spends significant time generating stack trace.
This PR uses statSync with throwIfNoEntry: false parameter to make it not throw.

Build performance improvement on my machine was around 10%.

Additional context

After profiling Vite 2.7 I found that resolve package is slow. After updating Vite, performance issue with resolve package was fixed, but I saw the same stack trace in Vite code. Tracked down resolve solution to this issue browserify/resolve#255. Backported this solution to Vite.

I could not find mentioned in the comment issue to test for that case. #2051 looks completely unrelated.

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.

[patak-dev]

This looks great, and I think we can get it in the next patch. Thanks @Demivan!