Add DEFAULT BND/NOBND to the change history, and explain the use case.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
\b Support \c{BND} prefix for branch instructions (for MPX).
+\b The \c{DEFAULT} directive can now take \c{BND} and \c{NOBND}
+options to indicate whether all relevant branches should be getting
+\c{BND} prefixes. This is expected to be the normal for use in MPX
+code.
+
\b Add \c{{evex}}, \c{{vex3}} and \c{{vex2}} instruction prefixes to
have NASM encode the corresponding instruction, if possible, with an EVEX,
3-byte VEX, or 2-byte VEX prefix, respectively.
\c{DEFAULT NOBND} can disable \c{DEFAULT BND} and then \c{BND} prefix will be
added only when explicitly specified in code.
+\c{DEFAULT BND} is expected to be the normal configuration for writing
+MPX-enabled code.
+
\H{section} \i\c{SECTION} or \i\c{SEGMENT}: Changing and \i{Defining
Sections}