Revert "Reapply [APInt] Enable APInt ctor assertion by default (llvm#114539)"

This reverts commit 3494ee9.

This change has exposed a bug in LLPC. Reverting for now until fixed.

Author: dstutt

llvm/include/llvm/ADT/APInt.h

@@ -109,7 +109,7 @@ class [[nodiscard]] APInt {
   /// \param implicitTrunc allow implicit truncation of non-zero/sign bits of
   ///                      val beyond the range of numBits
   APInt(unsigned numBits, uint64_t val, bool isSigned = false,
-        bool implicitTrunc = false)
+        bool implicitTrunc = true)
       : BitWidth(numBits) {
     if (!implicitTrunc) {
       if (isSigned) {