Fix Integer Rounding issue and duplicate definition of __deref in sal.h (dotnet/corec...

Fix Integer Rounding issue and duplicate definition of __deref in sal.h (dotnet/coreclr#22645)

* Fix large integer truncation

pal/pal.h:4988:43:
warning: large integer implicitly truncated to unsigned type
[-Woverflow]
     static const SIZE_T NoTargetFrameSp = SIZE_MAX;
                                                ^~~~~~~~

* Fix compilation error with GCC

/usr/include/c++/7.3.0/debug/functions.h:452:15: error: expected unqualified-id before ')' token
       __deref();
               ^
/usr/include/c++/7.3.0/debug/functions.h:455:34: error: expected primary-expression before '<' token
       typename = decltype(__deref<_It>() < __deref<_It>())>
                                  ^
/usr/include/c++/7.3.0/debug/functions.h:455:38: error: expected primary-expression before '>' token
       typename = decltype(__deref<_It>() < __deref<_It>())>
                                      ^
/usr/include/c++/7.3.0/debug/functions.h:455:40: error: expected primary-expression before ')' token
       typename = decltype(__deref<_It>() < __deref<_It>())>
                                        ^

Commit migrated from https://github.com/dotnet/coreclr/commit/f522e39d4a1da2a4b4859c5db5c741193d098984