Move a <wchar.h> implementation detail into the implementation.

No other C library expose these, and I couldn't find any callers.

Bug: http://b/62531921
Test: builds
Change-Id: I4a3505bc0897286a4036c48066b98d16665b573a
diff --git a/libc/bionic/wctype.cpp b/libc/bionic/wctype.cpp
index 77f8dde..8e2acef 100644
--- a/libc/bionic/wctype.cpp
+++ b/libc/bionic/wctype.cpp
@@ -36,6 +36,23 @@
 
 #include "private/icu.h"
 
+enum {
+  WC_TYPE_INVALID = 0,
+  WC_TYPE_ALNUM,
+  WC_TYPE_ALPHA,
+  WC_TYPE_BLANK,
+  WC_TYPE_CNTRL,
+  WC_TYPE_DIGIT,
+  WC_TYPE_GRAPH,
+  WC_TYPE_LOWER,
+  WC_TYPE_PRINT,
+  WC_TYPE_PUNCT,
+  WC_TYPE_SPACE,
+  WC_TYPE_UPPER,
+  WC_TYPE_XDIGIT,
+  WC_TYPE_MAX
+};
+
 static bool __icu_hasBinaryProperty(wint_t wc, UProperty property, int (*fallback)(int)) {
   typedef UBool (*FnT)(UChar32, UProperty);
   static auto u_hasBinaryProperty = reinterpret_cast<FnT>(__find_icu_symbol("u_hasBinaryProperty"));
diff --git a/libc/include/wchar.h b/libc/include/wchar.h
index d3e9f5c..c9a78be 100644
--- a/libc/include/wchar.h
+++ b/libc/include/wchar.h
@@ -42,23 +42,6 @@
 
 __BEGIN_DECLS
 
-enum {
-    WC_TYPE_INVALID = 0,
-    WC_TYPE_ALNUM,
-    WC_TYPE_ALPHA,
-    WC_TYPE_BLANK,
-    WC_TYPE_CNTRL,
-    WC_TYPE_DIGIT,
-    WC_TYPE_GRAPH,
-    WC_TYPE_LOWER,
-    WC_TYPE_PRINT,
-    WC_TYPE_PUNCT,
-    WC_TYPE_SPACE,
-    WC_TYPE_UPPER,
-    WC_TYPE_XDIGIT,
-    WC_TYPE_MAX
-};
-
 wint_t            btowc(int);
 int               fwprintf(FILE *, const wchar_t *, ...);
 int               fwscanf(FILE *, const wchar_t *, ...);