[AArch64] Correct inline assembly test case for S modifier [NFC]

[peter.smith]

Summary

The existing test for the AArch64 constraint S uses the A and L modifiers. These modifiers were implemented in the original AArch64 backend but were not carried forward to the merged backend. The A is associated with ADRP and does nothing, the L is associated with :lo12: . Given that A and L are not supported by GCC and not supported by the new implementation of constraint S in LLVM (see D46745) I've altered the test to put :lo12: directly in the string so that A and L are not needed. A recent use of S in the linux kernel can be found at https://github.com/torvalds/linux/commit/44a497abd621a71c645f06d3d545ae2f46448830

test/CodeGen/aarch64-inline-asm.c

void test_constraints_immed(void) {
     asm("and x0, x0, %0" : : "L"(0xaaaaaaaaaaaaaaaa) : "x0");
 // CHECK: call void asm sideeffect "add x0, x0, $0", "I,~{x0}"(i32 4095)
 // CHECK: call void asm sideeffect "and w0, w0, $0", "K,~{w0}"(i32 -1431655766)
 // CHECK: call void asm sideeffect "and x0, x0, $0", "L,~{x0}"(i64 -6148914691236517206)
 }
 
 void test_constraint_S(void) {
     int *addr;
-    asm("adrp %0, %A1\n\t"
-        "add %0, %0, %L1" : "=r"(addr) : "S"(&var));
-// CHECK: call i32* asm "adrp $0, ${1:A}\0A\09add $0, $0, ${1:L}", "=r,S"(i64* @var)
+    asm("adrp %0, %1\n\t"
+        "add %0, %0, :lo12:%1" : "=r"(addr) : "S"(&var));
+// CHECK: call i32* asm "adrp $0, $1\0A\09add $0, $0, :lo12:$1", "=r,S"(i64* @var)
 }
 
 void test_constraint_Q(void) {
     int val;
     asm("ldxr %0, %1" : "=r"(val) : "Q"(var));
 // CHECK: call i32 asm "ldxr $0, $1", "=r,*Q"(i64* @var)
 }