[mlir] Fix Analysis/Presburger/Utils.cpp compilation with GCC 11

[mlir] Fix Analysis/Presburger/Utils.cpp compilation with GCC 11

As reported in Issue #56850, mlir/lib/Analysis/Presburger/Utils.cpp doesn't
compile on Solaris 11.4/SPARC with the bundled GCC 11, as seen when testing
LLVM 15.0.0 rc1:

  /var/llvm/reltest/llvm-15.0.0-rc1/rc1/llvm-project/mlir/include/mlir/Analysis/Presburger/MPInt.h:260:47:
error: inlining failed in call to ‘always_inline’ ‘int64_t
mlir::presburger::int64FromMPInt(const mlir::presburger::MPInt&)’: indirect
function call with a yet undetermined callee

This patch hacks around this and allowed the build to finish.

Tested on `sparcv9-sun-solaris2.11`.

Differential Revision: https://reviews.llvm.org/D131060