Ensure that 64 bit variants of instruction sets are handled correctly

- Make sure to enable them based on the related 32bit instruction sets before disabling instruction sets that are enabled but not compatible with the instruction set hierarchy the runtime is designed for.

Author: davidwrighton

src/coreclr/src/pal/src/misc/jitsupport.cpp

@@ -126,4 +126,5 @@ PAL_GetJitCpuCapabilityFlags(CORJIT_FLAGS *flags)
 #endif // HAVE_AUXV_HWCAP_H
 #endif // defined(HOST_ARM64)
     CPUCompileFlags.Set64BitInstructionSetVariants();
+    CPUCompileFlags.EnsureValidInstructionSetSupport();
 }

src/coreclr/src/vm/codeman.cpp

@@ -1454,8 +1454,6 @@ void EEJitManager::SetCpuInfo()
                 CPUCompileFlags.Set(InstructionSet_BMI2);
             }
         }
-
-        CPUCompileFlags.EnsureValidInstructionSetSupport();
     }
 
     DWORD maxCpuIdEx = getcpuid(0x80000000, buffer);
@@ -1503,6 +1501,7 @@ void EEJitManager::SetCpuInfo()
 #endif // TARGET_ARM64
 
     CPUCompileFlags.Set64BitInstructionSetVariants();
+    CPUCompileFlags.EnsureValidInstructionSetSupport();
 
     m_CPUCompileFlags = CPUCompileFlags;
 }

src/coreclr/src/zap/zapper.cpp

@@ -1223,6 +1223,7 @@ void Zapper::InitializeCompilerFlags(CORCOMPILE_VERSION_INFO * pVersionInfo)
     }
 #endif // defined(TARGET_X86) || defined(TARGET_AMD64) || defined(TARGET_ARM64)
     m_pOpt->m_compilerFlags.Set64BitInstructionSetVariants();
+    m_pOpt->m_compilerFlags.EnsureValidInstructionSetSupport();
 
     if (   m_pOpt->m_compilerFlags.IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_INFO)
         && m_pOpt->m_compilerFlags.IsSet(CORJIT_FLAGS::CORJIT_FLAG_DEBUG_CODE)