Subzero: Implemented codegen for poisoning and unpoisoning stack redzones

tests_lit/asan_tests/alignment.ll

 ; Translate with -fsanitize-address and -O2 to test alignment and ordering of
 ; redzones when allocas are coalesced.
 
 ; REQUIRES: no_minimal_build
 
 ; RUN: %p2i --filetype=obj --disassemble --target x8632 -i %s --args -O2 \
 ; RUN:     -allow-externally-defined-symbols -fsanitize-address | FileCheck %s
 
 define internal i32 @func(i32 %arg1, i32 %arg2) {
   %l1 = alloca i8, i32 4, align 4
   %l2 = alloca i8, i32 5, align 1
   ret i32 42
 }
 
 ; CHECK: func
-; CHECK-NEXT: sub    esp,0xbc
-; CHECK-NEXT: lea    eax,[esp+0x10]
-; CHECK-NEXT: mov    DWORD PTR [esp],eax
-; CHECK-NEXT: mov    DWORD PTR [esp+0x4],0x20
-; CHECK-NEXT: __asan_poison
-; CHECK-NEXT: lea    eax,[esp+0x74]
-; CHECK-NEXT: mov    DWORD PTR [esp],eax
-; CHECK-NEXT: mov    DWORD PTR [esp+0x4],0x3c
-; CHECK-NEXT: __asan_poison
-; CHECK-NEXT: lea    eax,[esp+0x35]
-; CHECK-NEXT: mov    DWORD PTR [esp],eax
-; CHECK-NEXT: mov    DWORD PTR [esp+0x4],0x3b
-; CHECK-NEXT: __asan_poison
-; CHECK-NEXT: lea    eax,[esp+0x74]
-; CHECK-NEXT: mov    DWORD PTR [esp],eax
-; CHECK-NEXT: mov    DWORD PTR [esp+0x4],0x3c
-; CHECK-NEXT: __asan_unpoison
-; CHECK-NEXT: lea    eax,[esp+0x35]
-; CHECK-NEXT: mov    DWORD PTR [esp],eax
-; CHECK-NEXT: mov    DWORD PTR [esp+0x4],0x3b
-; CHECK-NEXT: __asan_unpoison
-; CHECK-NEXT: lea    eax,[esp+0x10]
-; CHECK-NEXT: mov    DWORD PTR [esp],eax
-; CHECK-NEXT: mov    DWORD PTR [esp+0x4],0x20
-; CHECK-NEXT: __asan_unpoison
+; CHECK-NEXT: sub    esp,0xa0
+; CHECK-NEXT: lea    eax,[esp]
+; CHECK-NEXT: shr    eax,0x3
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000000],0xffffffff
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000004],0xffffff04
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000008],0xffffffff
+; CHECK-NEXT: mov    DWORD PTR [eax+0x2000000c],0xffffff05
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000010],0xffffffff
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000000],0x0
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000004],0x0
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000008],0x0
+; CHECK-NEXT: mov    DWORD PTR [eax+0x2000000c],0x0
+; CHECK-NEXT: mov    DWORD PTR [eax+0x20000010],0x0
 ; CHECK-NEXT: mov    eax,0x2a
-; CHECK-NEXT: add    esp,0xbc
+; CHECK-NEXT: add    esp,0xa0
 ; CHECK-NEXT: ret