There are 450 tribool.hpp Wconversion warnings reported from 3 places when compiling HotSpot.

src/hotspot/share/utilities/tribool.hpp: In constructor 'TriBool::TriBool(bool)':
src/hotspot/share/utilities/tribool.hpp:43:44: warning: conversion from 'unsigned int' to 'unsigned char:2' may change value [-Wconversion]
   43 | TriBool(bool value) : _value(((u1)value) | 2) {}
      | ~~~~~~~~~~~~^~~
src/hotspot/share/utilities/tribool.hpp: In member function 'TriBool& TriBool::operator=(bool)':
src/hotspot/share/utilities/tribool.hpp:47:26: warning: conversion from 'unsigned int' to 'unsigned char:2' may change value [-Wconversion]
   47 | _value = ((u1)value) | 2;
      | ~~~~~~~~~~~~^~~
   
src/hotspot/share/utilities/tribool.hpp:76:26: warning: conversion from 'unsigned int' to 'unsigned char:2' may change value [-Wconversion]