[clang][bytecode] Allow adding offsets to function pointers (#105641)

Convert them to Pointers, do the offset calculation and then convert
them back to function pointers.

[clang][bytecode] Support ObjC blocks (#104551)

I started out by adding a new pointer type for blocks, and I was fully
prepared to compile their AST to bytecode and later call them.

... then I f

[clang][bytecode] Support ObjC blocks (#104551)

I started out by adding a new pointer type for blocks, and I was fully
prepared to compile their AST to bytecode and later call them.

... then I found out that the current interpreter doesn't support
calling blocks at all. So we reuse `Function` to support sources other
than `FunctionDecl`s and classify `BlockPointerType` as `PT_FnPtr`.

show more ...

[clang] Rename all AST/Interp stuff to AST/ByteCode (#104552)

"Interp" clashes with the clang interpreter and people often confuse
this.