Checking in vendor folder for ease of using go get.

vendor/golang.org/x/sys/cpu/cpu_gccgo.c

@@ -0,0 +1,43 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build 386 amd64 amd64p32
+// +build gccgo
+
+#include <cpuid.h>
+#include <stdint.h>
+
+// Need to wrap __get_cpuid_count because it's declared as static.
+int
+gccgoGetCpuidCount(uint32_t leaf, uint32_t subleaf,
+                   uint32_t *eax, uint32_t *ebx,
+                   uint32_t *ecx, uint32_t *edx)
+{
+	return __get_cpuid_count(leaf, subleaf, eax, ebx, ecx, edx);
+}
+
+// xgetbv reads the contents of an XCR (Extended Control Register)
+// specified in the ECX register into registers EDX:EAX.
+// Currently, the only supported value for XCR is 0.
+//
+// TODO: Replace with a better alternative:
+//
+//     #include <xsaveintrin.h>
+//
+//     #pragma GCC target("xsave")
+//
+//     void gccgoXgetbv(uint32_t *eax, uint32_t *edx) {
+//       unsigned long long x = _xgetbv(0);
+//       *eax = x & 0xffffffff;
+//       *edx = (x >> 32) & 0xffffffff;
+//     }
+//
+// Note that _xgetbv is defined starting with GCC 8.
+void
+gccgoXgetbv(uint32_t *eax, uint32_t *edx)
+{
+	__asm("  xorl %%ecx, %%ecx\n"
+	      "  xgetbv"
+	    : "=a"(*eax), "=d"(*edx));
+}