[arm64] Fix assertion in IsImmLLiteral and enable literal pool tests.

src/arm64/assembler-arm64.cc

Index: src/arm64/assembler-arm64.cc
diff --git a/src/arm64/assembler-arm64.cc b/src/arm64/assembler-arm64.cc
index e1074ab4404fb827a28189e22db511448474b0d8..7293d4eb5017734c1e0c552334bc8bcaed262eee 100644
--- a/src/arm64/assembler-arm64.cc
+++ b/src/arm64/assembler-arm64.cc
@@ -4429,6 +4429,8 @@ bool Assembler::IsImmLLiteral(int64_t offset) {
   int inst_size = static_cast<int>(kInstructionSizeLog2);
   bool offset_is_inst_multiple =
       (((offset >> inst_size) << inst_size) == offset);
+  DCHECK_GT(offset, 0);
+  offset >>= kLoadLiteralScaleLog2;
   return offset_is_inst_multiple && is_intn(offset, ImmLLiteral_width);
 }