Recognize triplets starting with armv5-, armv6- etc. And set the ARM arch version accordingly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66365 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/ARM/uxtb.ll b/test/CodeGen/ARM/uxtb.ll
index 85659a7..73e918b 100644
--- a/test/CodeGen/ARM/uxtb.ll
+++ b/test/CodeGen/ARM/uxtb.ll
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | llc -march=arm -mattr=+v6 | \
+; RUN: llvm-as < %s | llc -mtriple=armv6-apple-darwin | \
 ; RUN:   grep uxt | count 10
 
 define i32 @test1(i32 %x) {