[wpe-webkit] WebKit dropping explicit MIPS support

[Angelos Oikonomopoulos]

Hello,

we (Igalia) plan to discontinue our maintenance of WebKit on MIPS, which 
will also affect any WPE applications that require performant JavaScript.

- First, we will stop the MIPS buildbots for JSC on November 1st 2023.
- Soon afterwards, we plan to submit a patch to remove any MIPS-specific 
code (mainly JIT support).

The upcoming WPE 2.42 should be the last stable version to include 
platform-specific optimisation (such as JITs) for MIPS.

Beyond that, WebKit and JSC should keep working on MIPS using the CLOOP 
backend (though, if anyone depends on JSC on MIPS, they should test that 
it does). However, there will be no JIT support and the code will not 
even be build-tested.

If anyone has an interest in keeping WebKit working well on MIPS, please 
step up or contact us about it directly.

JFYI,
Angelos