Port the initial fast code generator to x64. For the constant true in

Port the initial fast code generator to x64.  For the constant true in
top-level code we generate:

 0  push rbp
 1  movq rbp,rsp
 4  push rsi
 5  push rdi
 6  push [r13+0x8]
10  cmpq rsp,[r13+0x0]
14  jnc 25  (0x7ff2c378ff19)
20  call 0x7ff2c377d260     ;; code: STUB, StackCheck, minor: 0
25  movq r10,0x7ff2e8608199    ;; object: 0x7ff2e8608199 <true>
35  push r10
37  movq rax,[rsp]
41  movq [rbp-0x18],rax
45  pop rax
46  push [rbp-0x18]
50  pop rax
51  movq rsp,rbp      ;; js return
54  pop rbp
55  ret 0x8
58  int3
59  int3
60  int3
61  int3
62  int3
63  int3
64  movq rax,[r13+0x8]
68  movq rsp,rbp      ;; js return
71  pop rbp
72  ret 0x8
75  int3
76  int3
77  int3
78  int3
79  int3
80  int3

Review URL: http://codereview.chromium.org/264066

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3071 ce2b1a6d-e550-0410-aec6-3dcde31c8c00