feat(transformer): drop this parameter from typescript functions

[Boshen]

Found another swc bug:

https://play.swc.rs/?version=1.3.94-nightly-20231016.1&code=H4sIAAAAAAAAA0vOzysuUShWsFWo5lIAguLUEoVcjZKMzGIrhepaHYWyxJzSVEMQWxOqAgSSgbryc1L1cvLTNSAqNMFytVy11gDKEf2ZUgAAAA%3D%3D&config=H4sIAAAAAAAAA1VPSQ7DIAy88wrkcw9tpV76hz4CUSciYhN2pKIofw%2BkkDY3exbPeBFSwkQannIpY1miSoTp2AtC2bP6FAQ4RySdTGS4dJapUoOyhDu0fhlglUbk6kK6X2%2BP5gAbAmF3NMwZb4b8n6mDiwmJzsIqVX60eE4ULRVceM872X6pfWuDcs0FPxH8lD3xuA6GXt3OaUaxbkujvRocAQAA

const s = {
    set m(this: {}, value1: {}) {
        console.log(value1)
    }
};

gets transformed to

const s = {
    set m (_this){
        console.log(value1);
    }
};

[magic-akari]

Great Investigation

[magic-akari]

Does this mean that we need to place a lot of AST visitor functions?
TypeScript AST are in many syntactic positions, and they produce a lot of extra statements.

However, when these AST visitor functions need to cooperate with each other in context, this will become very complicated.

[Boshen]

Nope, our codegen only prints javascript now so we don't need to remove nodes in the transformer.

[magic-akari]

It's a clever method.
So, I supposed there should be some methods, such as getInnerExpr, to get the JavaScript context AST that is wrapped by the TypeScript AST. Right?

[codspeed-hq]

CodSpeed Performance Report

Merging #1019 will not alter performance

_{Comparing ts-remove-this (e69b752) with main (ee134f0)}

Summary

✅ 22 untouched benchmarks