[libc][NFC] Tighten up guard conditions for sqrt and polyeval (#93791)

Found while investigating #93709

Author: gchatelet

libc/src/__support/FPUtil/sqrt.h

@@ -10,8 +10,9 @@
 #define LLVM_LIBC_SRC___SUPPORT_FPUTIL_SQRT_H
 
 #include "src/__support/macros/properties/architectures.h"
+#include "src/__support/macros/properties/cpu_features.h"
 
-#if defined(LIBC_TARGET_ARCH_IS_X86_64)
+#if defined(LIBC_TARGET_ARCH_IS_X86_64) && defined(LIBC_TARGET_CPU_HAS_SSE2)
 #include "x86_64/sqrt.h"
 #elif defined(LIBC_TARGET_ARCH_IS_AARCH64)
 #include "aarch64/sqrt.h"

libc/src/__support/FPUtil/x86_64/PolyEval.h

@@ -11,9 +11,10 @@
 
 #include "src/__support/common.h"
 #include "src/__support/macros/properties/architectures.h"
+#include "src/__support/macros/properties/cpu_features.h"
 
-#if !defined(LIBC_TARGET_ARCH_IS_X86)
-#error "Invalid include"
+#if !(defined(LIBC_TARGET_ARCH_IS_X86_64) && defined(LIBC_TARGET_CPU_HAS_SSE2))
+#error "sqrtss / sqrtsd need SSE2"
 #endif
 
 #include "src/__support/FPUtil/generic/sqrt.h"