SourceLevelDebugPkg/DebugAgent: Support IA32 processors without DE or FXSAVE/FXRESTOR

SourceLevelDebugPkg/DebugAgent: Support IA32 processors without DE or FXSAVE/FXRESTOR

Use CPUID Leaf 01 to detect support for debug extensions and FXSAVE/FXRESTOR instructions.
Do not enable those features in CR4 if they are not supported.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17220 6f19259b-4bc3-4df7-8a09-765794883524