Only keep the assume's that actually improve codegen

ConflictSet.cpp

@@ -143,20 +143,20 @@ private:
 };
 
 bool BitSet::test(int i) const {
-  assume(0 <= i);
+  assert(0 <= i);
-  assume(i < 256);
+  assert(i < 256);
   return words[i >> 6] & (uint64_t(1) << (i & 63));
 }
 
 void BitSet::set(int i) {
-  assume(0 <= i);
+  assert(0 <= i);
-  assume(i < 256);
+  assert(i < 256);
   words[i >> 6] |= uint64_t(1) << (i & 63);
 }
 
 void BitSet::reset(int i) {
-  assume(0 <= i);
+  assert(0 <= i);
-  assume(i < 256);
+  assert(i < 256);
   words[i >> 6] &= ~(uint64_t(1) << (i & 63));
 }
 
@@ -956,7 +956,7 @@ struct SearchStepWise {
   SearchStepWise() {}
   SearchStepWise(Node *n, std::span<const uint8_t> remaining)
       : n(n), remaining(remaining) {
-    assume(n->partialKeyLen == 0);
+    assert(n->partialKeyLen == 0);
   }
 
   bool step() {