.SAVE_PSECT stores the current program section context on the
    top of the program section context stack, an internal assembler
    stack. It leaves the current program section context in effect.
    The program section context stack can hold up to 50 entries.
    Each entry includes the value of the current location counter
    and the maximum value assigned to the location counter in the
    current program section. If the stack is full when .SAVE_PSECT is
    encountered, an error occurs.

    If the LOCAL_BLOCK option is specified, the current temporary
    label block is saved with the current program section context.

    .SAVE_PSECT and .RESTORE_PSECT are especially useful in macros
    that define program sections. See the description of .RESTORE_
    PSECT for an example using .SAVE_PSECT.