Rollback of add a declaration for __cpuid for the IntelLLVM compiler.

PiperOrigin-RevId: 534213948
Change-Id: I56b897060b9afe9d3d338756c80e52f421653b55

absl/crc/internal/cpu_detect.cc

@@ -34,11 +34,9 @@ namespace crc_internal {
 
 #if defined(__x86_64__) || defined(_M_X64)
 
-#if ABSL_HAVE_BUILTIN(__cpuid)
-// MSVC-equivalent __cpuid intrinsic declaration for clang-like compilers
-// for non-Windows build environments.
-extern void __cpuid(int[4], int);
-#elif !defined(_WIN32) && !defined(_WIN64)
+namespace {
+
+#if !defined(_WIN32) && !defined(_WIN64)
 // MSVC defines this function for us.
 // https://learn.microsoft.com/en-us/cpp/intrinsics/cpuid-cpuidex
 static void __cpuid(int cpu_info[4], int info_type) {
@@ -49,8 +47,6 @@ static void __cpuid(int cpu_info[4], int info_type) {
 }
 #endif  // !defined(_WIN32) && !defined(_WIN64)
 
-namespace {
-
 enum class Vendor {
   kUnknown,
   kIntel,

absl/random/internal/randen_detect.cc

@@ -45,10 +45,6 @@
 #if defined(ABSL_INTERNAL_USE_X86_CPUID)
 #if defined(_WIN32) || defined(_WIN64)
 #include <intrin.h>  // NOLINT(build/include_order)
-#elif ABSL_HAVE_BUILTIN(__cpuid)
-// MSVC-equivalent __cpuid intrinsic declaration for clang-like compilers
-// for non-Windows build environments.
-extern void __cpuid(int[4], int);
 #else
 // MSVC-equivalent __cpuid intrinsic function.
 static void __cpuid(int cpu_info[4], int info_type) {