Kernel: Support all Intel-defined CPUID feature flags for EAX=1

We're now able to detect all the regular CPUID feature flags from
ECX/EDX for EAX=1 :^)

None of the new ones are being used for anything yet, but they will show
up in /proc/cpuinfo and subsequently lscpu and SystemMonitor.

Note that I replaced the periods from the SSE 4.1 and 4.2 instructions
with underscores, which matches the internal enum names, Linux's
/proc/cpuinfo and the general pattern of replacing special characters
with underscores to limit feature names to [a-z0-9_].

The enum member stringification has been moved to a new function for
better re-usability and to avoid cluttering up Processor.cpp.

Kernel/Arch/x86/common/CPUID.cpp

@@ -0,0 +1,160 @@
+/*
+ * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Arch/x86/CPUID.h>
+
+namespace Kernel {
+
+StringView cpu_feature_to_string_view(CPUFeature::Type const& feature)
+{
+    if (feature == CPUFeature::SSE3)
+        return "sse3"sv;
+    if (feature == CPUFeature::PCLMULQDQ)
+        return "pclmulqdq"sv;
+    if (feature == CPUFeature::DTES64)
+        return "dtes64"sv;
+    if (feature == CPUFeature::MONITOR)
+        return "monitor"sv;
+    if (feature == CPUFeature::DS_CPL)
+        return "ds_cpl"sv;
+    if (feature == CPUFeature::VMX)
+        return "vmx"sv;
+    if (feature == CPUFeature::SMX)
+        return "smx"sv;
+    if (feature == CPUFeature::EST)
+        return "est"sv;
+    if (feature == CPUFeature::TM2)
+        return "tm2"sv;
+    if (feature == CPUFeature::SSSE3)
+        return "ssse3"sv;
+    // NOTE: This is called cid on Linux, but CNXT_ID in the Intel manual.
+    if (feature == CPUFeature::CNXT_ID)
+        return "cnxt_id"sv;
+    if (feature == CPUFeature::SDBG)
+        return "sdbg"sv;
+    if (feature == CPUFeature::FMA)
+        return "fma"sv;
+    if (feature == CPUFeature::CX16)
+        return "cx16"sv;
+    if (feature == CPUFeature::XTPR)
+        return "xtpr"sv;
+    if (feature == CPUFeature::PDCM)
+        return "pdcm"sv;
+    if (feature == CPUFeature::PCID)
+        return "pcid"sv;
+    if (feature == CPUFeature::DCA)
+        return "dca"sv;
+    if (feature == CPUFeature::SSE4_1)
+        return "sse4_1"sv;
+    if (feature == CPUFeature::SSE4_2)
+        return "sse4_2"sv;
+    if (feature == CPUFeature::X2APIC)
+        return "x2apic"sv;
+    if (feature == CPUFeature::MOVBE)
+        return "movbe"sv;
+    if (feature == CPUFeature::POPCNT)
+        return "popcnt"sv;
+    // NOTE: This is called tsc_deadline_timer on Linux, but TSC_DEADLINE in the Intel manual.
+    if (feature == CPUFeature::TSC_DEADLINE)
+        return "tsc_deadline"sv;
+    if (feature == CPUFeature::AES)
+        return "aes"sv;
+    if (feature == CPUFeature::XSAVE)
+        return "xsave"sv;
+    if (feature == CPUFeature::OSXSAVE)
+        return "osxsave"sv;
+    if (feature == CPUFeature::AVX)
+        return "avx"sv;
+    if (feature == CPUFeature::F16C)
+        return "f16c"sv;
+    if (feature == CPUFeature::RDRAND)
+        return "rdrand"sv;
+    if (feature == CPUFeature::HYPERVISOR)
+        return "hypervisor"sv;
+    if (feature == CPUFeature::FPU)
+        return "fpu"sv;
+    if (feature == CPUFeature::VME)
+        return "vme"sv;
+    if (feature == CPUFeature::DE)
+        return "de"sv;
+    if (feature == CPUFeature::PSE)
+        return "pse"sv;
+    if (feature == CPUFeature::TSC)
+        return "tsc"sv;
+    if (feature == CPUFeature::MSR)
+        return "msr"sv;
+    if (feature == CPUFeature::PAE)
+        return "pae"sv;
+    if (feature == CPUFeature::MCE)
+        return "mce"sv;
+    if (feature == CPUFeature::CX8)
+        return "cx8"sv;
+    if (feature == CPUFeature::APIC)
+        return "apic"sv;
+    if (feature == CPUFeature::SEP)
+        return "sep"sv;
+    if (feature == CPUFeature::MTRR)
+        return "mtrr"sv;
+    if (feature == CPUFeature::PGE)
+        return "pge"sv;
+    if (feature == CPUFeature::MCA)
+        return "mca"sv;
+    if (feature == CPUFeature::CMOV)
+        return "cmov"sv;
+    if (feature == CPUFeature::PAT)
+        return "pat"sv;
+    if (feature == CPUFeature::PSE36)
+        return "pse36"sv;
+    if (feature == CPUFeature::PSN)
+        return "psn"sv;
+    if (feature == CPUFeature::CLFLUSH)
+        return "clflush"sv;
+    if (feature == CPUFeature::DS)
+        return "ds"sv;
+    if (feature == CPUFeature::ACPI)
+        return "acpi"sv;
+    if (feature == CPUFeature::MMX)
+        return "mmx"sv;
+    if (feature == CPUFeature::FXSR)
+        return "fxsr"sv;
+    if (feature == CPUFeature::SSE)
+        return "sse"sv;
+    if (feature == CPUFeature::SSE2)
+        return "sse2"sv;
+    if (feature == CPUFeature::SS)
+        return "ss"sv;
+    if (feature == CPUFeature::HTT)
+        return "htt"sv;
+    if (feature == CPUFeature::TM)
+        return "tm"sv;
+    if (feature == CPUFeature::IA64)
+        return "ia64"sv;
+    if (feature == CPUFeature::PBE)
+        return "pbe"sv;
+    if (feature == CPUFeature::SMEP)
+        return "smep"sv;
+    if (feature == CPUFeature::RDSEED)
+        return "rdseed"sv;
+    if (feature == CPUFeature::SMAP)
+        return "smap"sv;
+    if (feature == CPUFeature::UMIP)
+        return "umip"sv;
+    if (feature == CPUFeature::SYSCALL)
+        return "syscall"sv;
+    if (feature == CPUFeature::NX)
+        return "nx"sv;
+    if (feature == CPUFeature::RDTSCP)
+        return "rdtscp"sv;
+    if (feature == CPUFeature::LM)
+        return "lm"sv;
+    if (feature == CPUFeature::CONSTANT_TSC)
+        return "constant_tsc"sv;
+    if (feature == CPUFeature::NONSTOP_TSC)
+        return "nonstop_tsc"sv;
+    VERIFY_NOT_REACHED();
+}
+
+}