Add misclassified C sample (#3652)

This sample is misclassified as Objective-C.

samples/C/cpuid.h

@@ -0,0 +1,25 @@
+#ifndef CPUID_H
+#define CPUID_H
+
+#include "misc.h"
+
+static inline void do_cpuid(dword_t *eax, dword_t *ebx, dword_t *ecx, dword_t *edx) {
+    dword_t leaf = *eax;
+    switch (leaf) {
+        case 0:
+            *eax = 0x01; // we support barely anything
+            *ebx = 0x756e6547; // Genu
+            *edx = 0x49656e69; // ineI
+            *ecx = 0x6c65746e; // ntel
+            break;
+        default: // if leaf is too high, use highest supported leaf
+        case 1:
+            *eax = 0x0; // say nothing about cpu model number
+            *ebx = 0x0; // processor number 0, flushes 0 bytes on clflush
+            *ecx = 0b00000000000000000000000000000000; // we support none of the features in ecx
+            *edx = 0b00000000000000000000000000000000; // we also support none of the features in edx
+            break;
+    }
+}
+
+#endif