[RISCV] Use static arrays+ArrayRef instead of SmallVector to select P extension vector VTs. NFC (#175390)

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 9a72e8a..b23bffb 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -526,16 +526,18 @@
     setTargetDAGCombine(ISD::TRUNCATE);
     setTruncStoreAction(MVT::v2i32, MVT::v2i16, Expand);
     setTruncStoreAction(MVT::v4i16, MVT::v4i8, Expand);
-    SmallVector<MVT, 2> VTs;
+    static const MVT RV32VTs[] = {MVT::v2i16, MVT::v4i8};
+    static const MVT RV64VTs[] = {MVT::v2i32, MVT::v4i16, MVT::v8i8};
+    ArrayRef<MVT> VTs;
     if (Subtarget.is64Bit()) {
-      VTs.append({MVT::v2i32, MVT::v4i16, MVT::v8i8});
+      VTs = RV64VTs;
       setTruncStoreAction(MVT::v2i64, MVT::v2i32, Expand);
       setTruncStoreAction(MVT::v4i32, MVT::v4i16, Expand);
       setTruncStoreAction(MVT::v8i16, MVT::v8i8, Expand);
       setTruncStoreAction(MVT::v2i32, MVT::v2i16, Expand);
       setTruncStoreAction(MVT::v4i16, MVT::v4i8, Expand);
     } else {
-      VTs.append({MVT::v2i16, MVT::v4i8});
+      VTs = RV32VTs;
       setOperationAction(ISD::BUILD_VECTOR, MVT::v4i8, Custom);
     }
     setOperationAction(ISD::UADDSAT, VTs, Legal);