[AArch64] Remove an unnecessary restriction on pre-index instructions.

Previously, the index was constrained to the size of the memory operation for
no apparent reason.  This change removes that constraint so that we can form
pre-index instructions with any valid offset.

llvm-svn: 248931
diff --git a/llvm/test/CodeGen/AArch64/fastcc.ll b/llvm/test/CodeGen/AArch64/fastcc.ll
index 9917fcd..f021eb2 100644
--- a/llvm/test/CodeGen/AArch64/fastcc.ll
+++ b/llvm/test/CodeGen/AArch64/fastcc.ll
@@ -7,12 +7,12 @@
 define fastcc void @func_stack0() {
 ; CHECK-LABEL: func_stack0:
 ; CHECK: mov x29, sp
-; CHECK-NEXT: sub sp, sp, #32
+; CHECK: str w{{[0-9]+}}, [sp, #-32]!
 
 ; CHECK-TAIL-LABEL: func_stack0:
 ; CHECK-TAIL: stp x29, x30, [sp, #-16]!
 ; CHECK-TAIL-NEXT: mov x29, sp
-; CHECK-TAIL-NEXT: sub sp, sp, #32
+; CHECK-TAIL: str w{{[0-9]+}}, [sp, #-32]!
 
 
   call fastcc void @func_stack8([8 x i32] undef, i32 42)
@@ -55,13 +55,13 @@
 ; CHECK-LABEL: func_stack8:
 ; CHECK: stp x29, x30, [sp, #-16]!
 ; CHECK: mov x29, sp
-; CHECK: sub sp, sp, #32
+; CHECK: str w{{[0-9]+}}, [sp, #-32]!
 
 
 ; CHECK-TAIL-LABEL: func_stack8:
 ; CHECK-TAIL: stp x29, x30, [sp, #-16]!
 ; CHECK-TAIL: mov x29, sp
-; CHECK-TAIL: sub sp, sp, #32
+; CHECK-TAIL: str w{{[0-9]+}}, [sp, #-32]!
 
 
   call fastcc void @func_stack8([8 x i32] undef, i32 42)