Enum size checks in Base.h (UINT32 not ISO C compatible)

["Rebecca Cran" <rebecca@bsdio.com>]

In commit 6440385b17def888544c2454ffba58384b929a22 
(https://github.com/tianocore/edk2/commit/6440385b17def888544c2454ffba58384b929a22) 
enum size checks were added.

However, according to gcc, ISO C restricts the size of enum values to 
int; building with -std=c11 -pedantic results in the error:

MdePkg/Include/Base.h:812:28: error: ISO C restricts enumerator values 
to range of ‘int’ [-Werror=pedantic]
   812 |   __VerifyInt32EnumValue = 0xffffffff

Replacing 0xffffffff with 0x7fffffff fixes the problem.

It looks like this might change in C23, but since the use of 
_Static_assert in Base.h we require at least C11 (and I suspect most 
compilers aren't C23 compliant) which states:

"The expression that defines the value of an enumeration constant shall 
be an integer constant expression that has a value representable as an int.
[Section 6.7.2.2]"

The UEFI Specification appears to say we require an INT32 (i.e. a signed 
int) so is the existing code wrong?

-- 
Rebecca Cran