As threatened, here is my first round of bashing on the internals 
manual. Eli, how does it look to you?

Stan

2008-06-28  Stan Shebs  <stan@codesourcery.com>

    * gdbint.texinfo: General round of cleanup and minor
    clarifications.
    (Breakpoint Handling): Remove mention of BREAKPOINT macro.
    (Longjmp Support): Update description to reflect how it is done
    for targets without using native header.
    (Symbol Handling): Add a little more general explanation.
    (COFF, ELF): Mention stabs encapsulation.
    (DWARF 3): New section.
    (Adding a New Host): Scrub out some obsolete bits.
    (Generic Host Support Files): Mention ser-pipe.c, ser-mingw.c.
    (Host Conditionals): Remove descriptions of NO_STD_REGS,
    HAVE_MMAP, HAVE_TERMIO, INT_MAX etc, LONGEST, HAVE_LONG_DOUBLE,
    PRINTF_HAS_LONG_DOUBLE, SCANF_HAS_LONG_DOUBLE, L_SET, SEEK_CUR,
    SEEK_SET, STOP_SIGNAL, USG.
    (Raw and Virtual Register Representations): Ditto for
    DEPRECATED_REGISTER_RAW_SIZE, DEPRECATED_REGISTER_VIRTUAL_SIZE,
    DEPRECATED_REGISTER_VIRTUAL_TYPE, REGISTER_CONVERT_TO_TYPE.
    (Target Conditionals): Ditto for DEPRECATED_FP_REGNUM,
    DEPRECATED_FRAMELESS_FUNCTION_INVOCATION, DEPRECATED_FRAME_CHAIN,
    DEPRECATED_FRAME_CHAIN_VALID, DEPRECATED_FRAME_INIT_SAVED_REGS,
    DEPRECATED_FRAME_SAVED_PC, DEPRECATED_FUNCTION_START_OFFSET,
    DEPRECATED_REGISTER_VIRTUAL_SIZE,
    DEPRECATED_REGISTER_VIRTUAL_TYPE,
    DEPRECATED_USE_STRUCT_CONVENTION.
    Describe gdbarch_deprecated_fp_regnum.
    Update description of gdbarch_print_insn.
    (Adding a New Target): Scrub out obsolete bits.
    (Obsolete Conditionals): Remove entire section.