Add explicit triples to AArch64 tests

Only Linux is supported at the moment, and other platforms quickly fault. As a
result these tests would fail on non-Linux hosts. It may be worth making the
tests more generic again as more platforms are supported.

llvm-svn: 174170
diff --git a/llvm/test/CodeGen/AArch64/inline-asm-constraints-badL.ll b/llvm/test/CodeGen/AArch64/inline-asm-constraints-badL.ll
index 90da9ba..4f00398 100644
--- a/llvm/test/CodeGen/AArch64/inline-asm-constraints-badL.ll
+++ b/llvm/test/CodeGen/AArch64/inline-asm-constraints-badL.ll
@@ -1,4 +1,4 @@
-; RUN: not llc -march=aarch64 < %s
+; RUN: not llc -mtriple=aarch64-none-linux-gnu < %s
 
 define void @foo() {
   ; 32-bit bitpattern ending in 1101 can't be produced.