[flang] [llvm] [flang] implement show_descriptor intrinsic, a non-standard extension (PR #169137)

[Slava Zakharin via llvm-commits]

================
@@ -398,6 +398,15 @@ std::int64_t RTNAME(time)() { return time(nullptr); }
 // MCLOCK: returns accumulated CPU time in ticks
 std::int32_t FORTRAN_PROCEDURE_NAME(mclock)() { return std::clock(); }
 
+void RTNAME(ShowDescriptor)(const char *descr) {
----------------
vzakhari wrote:

Can we declare the argument as `const Fortran::runtime::Descriptor *`?

https://github.com/llvm/llvm-project/pull/169137