[APInt] Removed redundant assert and condition in APInt::SetBits (llvm#138038)

During [pull request](llvm#137098) it was suggested that I remove these redundant parts of APInt::SetBits.

Author: liamsemeria

llvm/include/llvm/ADT/APInt.h

@@ -1366,11 +1366,10 @@ class [[nodiscard]] APInt {
   /// This function handles case when \p loBit <= \p hiBit.
   void setBits(unsigned loBit, unsigned hiBit) {
     assert(hiBit <= BitWidth && "hiBit out of range");
-    assert(loBit <= BitWidth && "loBit out of range");
     assert(loBit <= hiBit && "loBit greater than hiBit");
     if (loBit == hiBit)
       return;
-    if (loBit < APINT_BITS_PER_WORD && hiBit <= APINT_BITS_PER_WORD) {
+    if (hiBit <= APINT_BITS_PER_WORD) {
       uint64_t mask = WORDTYPE_MAX >> (APINT_BITS_PER_WORD - (hiBit - loBit));
       mask <<= loBit;
       if (isSingleWord())