fix(@babel/parser): fix tokenizer context update code

[Eyoatam]

Q	A
Patch: Bug Fix?	Yes
Tests Added + Pass?	Yes
License	MIT

this will always be false since b_stat does not exist on the types object. so instead of types.b_stat use types.braceStatement

[babel-bot]

Build successful! You can test your changes in the REPL here: https://babeljs.io/repl/build/46691/

[codesandbox-ci]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

Latest deployment of this branch, based on commit 42d35a8:

Sandbox	Source
babel-repl-custom-plugin	Configuration
babel-plugin-multi-config	Configuration

[JLHwung]

Good catch! We should add a test for this change.

While it is very likely to be a typo, I think we should add a test to actually cover this branch.

[JLHwung]

This change is not visible to users.

Before this PR, the first slash in { function x () {} /1/ } is tokenized as a slash (incorrect!) but later we are saved from the parser#parseExprAtom where we re-read as a regex token:

babel/packages/babel-parser/src/parser/expression.js

Line 993 in 4eda1c8

if (this.state.type === tt.slash) this.readRegexp();

After this PR, such token is handled as regexp token in the first place. So this PR does not introduce changing behaviours.

[JLHwung]

I marked this PR as internal because of no visible behaviour changes.