A thread can obtain the invocation context of the procedure
    context preceding any other procedure context by using this
    function.

    Format
      LIB$X86_GET_PREV_INVO_CONTEXT(invo_context)

1  –  Returns

 status

    A value of 1 indicates success. When the initial context
    represents the bottom of the call stack, a value of 0 is
    returned.

2  –  Argument

 invo_context

    OpenVMS usage: invo_context_blk
    type:          structure
    access:        modify
    mechanism:     by reference

    Address of a valid invocation context block. The given
    invocation context block is updated to represent the context of
    the previous (calling) frame.

    The LIBICB$V_BOTTOM_OF_STACK flag of the invocation context
    block is set if the target frame represents the end of the
    invocation call chain or if stack corruption is detected.