[RemoveDIs] Update DIBuilder C API and OCaml bindings [2/2] (#86529)

Follow on from #84915 which adds the DbgRecord function variants. The C API
changes were reviewed in #85657.

# C API

Update the LLVMDIBuilderInsert... functions to insert DbgRecords instead
of debug intrinsics.

    LLVMDIBuilderInsertDeclareBefore
    LLVMDIBuilderInsertDeclareAtEnd
    LLVMDIBuilderInsertDbgValueBefore
    LLVMDIBuilderInsertDbgValueAtEnd

Calling these functions will now cause an assertion if the module is in the
wrong debug info format. They should only be used when the module is in "new
debug format".

Use LLVMIsNewDbgInfoFormat to query and LLVMSetIsNewDbgInfoFormat to change the
debug info format of a module.

Please see https://llvm.org/docs/RemoveDIsDebugInfo.html#c-api-change
(RemoveDIsDebugInfo.md) for more info.

# OCaml bindings

Add set_is_new_dbg_info_format and is_new_dbg_info_format to the OCaml bindings.
These can be used to set and query the current debug info mode. These wi...