[x86] Fix the RUN-lines of this test to make sense.

I got them quite wrong when updating it and had the SSE4.1 run checked
for SSE2 and the SSE2 run checked for SSE4.1. I think everything was
actually generic SSE, but this still seems good to fix. While here,
hoist the triple into the IR and make the flag set a bit more direct in
what it is trying to test.

llvm-svn: 218978
diff --git a/llvm/test/CodeGen/X86/sse-scalar-fp-arith.ll b/llvm/test/CodeGen/X86/sse-scalar-fp-arith.ll
index e6a6d99..b122ef6 100644
--- a/llvm/test/CodeGen/X86/sse-scalar-fp-arith.ll
+++ b/llvm/test/CodeGen/X86/sse-scalar-fp-arith.ll
@@ -1,6 +1,8 @@
-; RUN: llc -mtriple=x86_64-pc-linux -mcpu=corei7 < %s | FileCheck --check-prefix=SSE --check-prefix=SSE2 %s
-; RUN: llc -mtriple=x86_64-pc-linux -mattr=-sse4.1 -mcpu=corei7 < %s | FileCheck --check-prefix=SSE --check-prefix=SSE41 %s
-; RUN: llc -mtriple=x86_64-pc-linux -mcpu=corei7-avx < %s | FileCheck --check-prefix=AVX %s
+; RUN: llc -mcpu=x86-64 -mattr=+sse2 < %s | FileCheck --check-prefix=SSE --check-prefix=SSE2 %s
+; RUN: llc -mcpu=x86-64 -mattr=+sse4.1 < %s | FileCheck --check-prefix=SSE --check-prefix=SSE41 %s
+; RUN: llc -mcpu=x86-64 -mattr=+avx < %s | FileCheck --check-prefix=AVX %s
+
+target triple = "x86_64-unknown-unknown"
 
 ; Ensure that the backend no longer emits unnecessary vector insert
 ; instructions immediately after SSE scalar fp instructions