stdlib: repair 32bit non-Darwin build for TypeLayout

glibc's `uintptr_t` and `uint64_t` are both `unsigned long int`, but `uint32_t`
is `unsigned int`, so BitVector overloads cannot be resoled on 32-bit
platforms by following compilation error:

error: call to member function 'add' is ambiguous
  bv.add(heap_object_abi::SwiftSpareBitsMask);

darwin 32-bit platforms use stdint types defined in SwiftStdint.h, so
they are identical

Author: kateinoigakukun

stdlib/toolchain/CompatibilityBytecodeLayouts/BytecodeLayouts.cpp

@@ -75,6 +75,14 @@ size_t BitVector::count() const {
   return total;
 }
 
+void BitVector::add(uintptr_t byte) {
+#if __POINTER_WIDTH__ == 64
+  add((uint64_t)byte);
+#else
+  add((uint32_t)byte);
+#endif
+}
+
 void BitVector::add(uint64_t byte) {
   for (size_t i = 0; i < 64; i++)
     data.push_back(byte >> (63 - i) & 0x1);

stdlib/toolchain/CompatibilityBytecodeLayouts/BytecodeLayouts.h

@@ -159,6 +159,9 @@ struct BitVector {
   /// Append on a 64bit value
   void add(uint64_t values);
 
+  /// Append on a pointer-size value
+  void add(uintptr_t values);
+
   /// Append on a vector of bytes
   void add(std::vector<uint8_t> values);