Fix build on win/clang

EmbeddedCharcodeFromUnicode is not used on windows anymore and clang complains.

TBR=weili@chromium.org

Review URL: https://codereview.chromium.org/1828673002 .
diff --git a/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp b/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
index 351df60..98051cb 100644
--- a/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
+++ b/core/fpdfapi/fpdf_font/fpdf_font_cid.cpp
@@ -298,6 +298,7 @@
 }
 
 #if _FXM_PLATFORM_ != _FXM_PLATFORM_WINDOWS_
+
 FX_DWORD EmbeddedCharcodeFromUnicode(const FXCMAP_CMap* pEmbedMap,
                                      CIDSet charset,
                                      FX_WCHAR unicode) {
@@ -321,7 +322,6 @@
   }
   return 0;
 }
-#endif  // _FXM_PLATFORM_ != _FXM_PLATFORM_WINDOWS_
 
 FX_WCHAR EmbeddedUnicodeFromCharcode(const FXCMAP_CMap* pEmbedMap,
                                      CIDSet charset,
@@ -344,6 +344,8 @@
   return 0;
 }
 
+#endif  // _FXM_PLATFORM_ != _FXM_PLATFORM_WINDOWS_
+
 void FT_UseCIDCharmap(FXFT_Face face, int coding) {
   int encoding;
   switch (coding) {