[X86][AVX] Fixed v16i16/v32i8 ADD/SUB costs on AVX1 subtargets

Add explicit v16i16/v32i8 ADD/SUB costs, matching the costs of v4i64/v8i32 - they were missing for some reason.

This has side effects on the LV max bandwidth tests (AVX1 now prefers 128-bit vectors vs AVX2 which still prefers 256-bit)

llvm-svn: 286832
diff --git a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
index 7029a02..5b3091e 100644
--- a/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
+++ b/llvm/lib/Target/X86/X86TargetTransformInfo.cpp
@@ -526,6 +526,10 @@
     // Two ops + 1 extract + 1 insert = 4.
     { ISD::MUL,     MVT::v16i16,   4 },
     { ISD::MUL,     MVT::v8i32,    4 },
+    { ISD::SUB,     MVT::v32i8,    4 },
+    { ISD::ADD,     MVT::v32i8,    4 },
+    { ISD::SUB,     MVT::v16i16,   4 },
+    { ISD::ADD,     MVT::v16i16,   4 },
     { ISD::SUB,     MVT::v8i32,    4 },
     { ISD::ADD,     MVT::v8i32,    4 },
     { ISD::SUB,     MVT::v4i64,    4 },