[MLIR][Flang][DebugInfo] Set debug info format in MLIR->IR translation (#95098)

MLIR's LLVM dialect does not internally support debug records, only
converting to/from debug intrinsics. To smooth the transition from
intrinsics to records, there is a step prior to IR->MLIR translation
that switches the IR module to intrinsic-form; this patch adds the
equivalent conversion to record-form at MLIR->IR translation, and also
modifies the flang front end to use the WriteNewDbgInfoFormat flag when
it is emitting LLVM IR.