[llvm] [SystemZ][z/OS] Refactor AutoConvert.h to remove large MVS guard (PR #143174)

[Sean Perry via llvm-commits]

================
@@ -28,16 +29,55 @@
 #ifdef __cplusplus
 extern "C" {
 #endif /* __cplusplus */
+
 int enablezOSAutoConversion(int FD);
----------------
perry-ca wrote:

How are these C variations of the functions handled?  Do we declare macros for enableAutoConversion() if not c++ and expand that to enablezOSAutoConversion() for MVS?  And how does this integrate with the c++ inline functions?  It might be the inline functions for c++ call these extern "C" functions for z/OS instead of having the z/OS function in the llvm namespace that returns std::error_code.

https://github.com/llvm/llvm-project/pull/143174