For compatibility with the Compaq C compiler, the following pragma is supported.
extern_prefix
stringextern_prefix
pragma with the
empty string.
This pragma is similar in intent to to the asm labels extension
(see Asm Labels) in that the system programmer wants to change
the assembly-level ABI without changing the source-level API. The
preprocessor defines __PRAGMA_EXTERN_PREFIX
if the pragma is
available.