[RISCV] Rename assembler mnemonic of unordered floating-point reductions for v1.0-rc change

Rename vfredsum and vfwredsum to vfredusum and vfwredusum. Add aliases for vfredsum and vfwredsum.

Reviewed By: luismarques, HsiangKai, khchen, frasercrmck, kito-cheng, craig.topper

Differential Revision: https://reviews.llvm.org/D105690
diff --git a/clang/include/clang/Basic/riscv_vector.td b/clang/include/clang/Basic/riscv_vector.td
index 5ef5874..6de76aa 100644
--- a/clang/include/clang/Basic/riscv_vector.td
+++ b/clang/include/clang/Basic/riscv_vector.td
@@ -2006,11 +2006,11 @@
 // 15.3. Vector Single-Width Floating-Point Reduction Instructions
 defm vfredmax : RVVFloatingReductionBuiltin;
 defm vfredmin : RVVFloatingReductionBuiltin;
-defm vfredsum : RVVFloatingReductionBuiltin;
+defm vfredusum : RVVFloatingReductionBuiltin;
 defm vfredosum : RVVFloatingReductionBuiltin;
 
 // 15.4. Vector Widening Floating-Point Reduction Instructions
-defm vfwredsum : RVVFloatingWidenReductionBuiltin;
+defm vfwredusum : RVVFloatingWidenReductionBuiltin;
 defm vfwredosum : RVVFloatingWidenReductionBuiltin;
 }