Reland "Turn libbase into a component"

src/base/cpu.h

Index: src/base/cpu.h
diff --git a/src/base/cpu.h b/src/base/cpu.h
index 19d4102f5b4fe618456ab9f6af453b5258c187fc..e0fcea1ca0350692bbc0c2268f2377de6f119858 100644
--- a/src/base/cpu.h
+++ b/src/base/cpu.h
@@ -13,6 +13,7 @@
 #ifndef V8_BASE_CPU_H_
 #define V8_BASE_CPU_H_
 
+#include "src/base/base-export.h"
 #include "src/base/macros.h"
 
 namespace v8 {
@@ -28,7 +29,7 @@ namespace base {
 // architectures. For each architecture the file cpu_<arch>.cc contains the
 // implementation of these static functions.
 
-class CPU final {
+class V8_BASE_EXPORT CPU final {
  public:
   CPU();