gas64: some changes in comments and removal of some asm_info()

(cherry picked from commit 67cdf68)

gas64 : fix incomplete test in optimization module
(cherry picked from commit f78ce79)

gas64 : new optimizations

mov -xxx[rbp], rax --> mov -xxx[rbp], rax kept
mov rcx, -xxx[rbp] --> #2 mov rcx, -xxx[rbp] commented
mov rcx, rax new line

movq -xxx[rbp], xmm0 --> movq -xxx[rbp], xmm0 kept
movq xmm1, -xxx[rbp] --> #3 movq xmm1, -xxx[rbp] commented
movsd xmm1, xmm0 new line
(cherry picked from commit 170d5db)

gas64 : fix wrong use of test sse41 when converting float to ulongint causing use of roundss/roundsd even with CPU non compatible
(cherry picked from commit 1b8d94a)

gas64 : removal of useless test in optimization (optim 3-1)
(cherry picked from commit 61cacf2)

gas64 : all 4 leading spaces replaced by tab (thanks to Notepad++)
	'By SARG' added (removed by error)
(cherry picked from commit 023cfeb)

gas64 : fix new optimizations....
(cherry picked from commit ff7867b)

Merge pull request #262 from SARG-FB/gas64_rev

gas64; sse41 checks and optimization fixes

- fix sse41 test, before the asm test instruction was wrongly used.
- fix wrong optimization for xmmN registers.
- new optimizations canceling the above fix.
- some changes in asm_info() lines, typos fixes
(cherry picked from commit ab9fbd3)

Author: SARG-FB