[X86] Add family/model for Intel Comet Lake CPUs for -march=native and function multiversioning

This adds the family/model returned by CPUID for some Intel
Comet Lake CPUs. Instruction set and tuning wise these are
the same as "skylake".

These are not in the Intel SDM yet, but these should be correct.

lib/Support/Host.cpp

@@ -700,6 +700,8 @@ getIntelProcessorTypeAndSubtype(unsigned Family, unsigned Model,
     case 0x5e:              // Skylake desktop
     case 0x8e:              // Kaby Lake mobile
     case 0x9e:              // Kaby Lake desktop
+    case 0xa5:              // Comet Lake-H/S
+    case 0xa6:              // Comet Lake-U
       *Type = X86::INTEL_COREI7; // "skylake"
       *Subtype = X86::INTEL_COREI7_SKYLAKE;
       break;