[mono] use -Werror=shorten-64-to-32 and -Werror=implicit-int-conversion

Follow-up to dotnet#69236

Related to dotnet#70026

Author: lambdageek

src/mono/CMakeLists.txt

@@ -507,6 +507,7 @@ if(GCC)
 
   if (CMAKE_C_COMPILER_ID MATCHES "Clang")
     set(WARNINGS "${WARNINGS} -Qunused-arguments -Wno-tautological-compare -Wno-parentheses-equality -Wno-self-assign -Wno-return-stack-address -Wno-constant-logical-operand -Wno-zero-length-array -Wno-asm-operand-widths")
+    append("-Werror=shorten-64-to-32 -Werror=implicit-int-conversion" WERROR)
   endif()
 
   check_c_compiler_flag("-Werror=incompatible-pointer-types" WERROR_INCOMPATIBLE_POINTER_TYPES)