Revert "[clang][bytecode] Handle bitcasts involving bitfields (llvm#116843)"

This reverts commit 4b5e7fa.

This breaks builders:
https://lab.llvm.org/buildbot/#/builders/154/builds/8464

I guess some more testing on 32 bit hosts is needed.

Author: tbaederr

clang/lib/AST/ByteCode/BitcastBuffer.cpp

@@ -82,7 +82,9 @@ class Boolean final {
   Boolean truncate(unsigned TruncBits) const { return *this; }
 
   static Boolean bitcastFromMemory(const std::byte *Buff, unsigned BitWidth) {
-    // Just load the first byte.
+    // Boolean width is currently always 8 for all supported targets. If this
+    // changes we need to get the bool width from the target info.
+    assert(BitWidth == 8);
     bool Val = static_cast<bool>(*Buff);
     return Boolean(Val);
   }

clang/lib/AST/ByteCode/BitcastBuffer.h

@@ -183,7 +183,6 @@ template <unsigned Bits, bool Signed> class Integral final {
   }
 
   Integral truncate(unsigned TruncBits) const {
-    assert(TruncBits >= 1);
     if (TruncBits >= Bits)
       return *this;
     const ReprT BitMask = (ReprT(1) << ReprT(TruncBits)) - 1;