Replace uses of std::iswdigit() with FXSYS_IsDecimalDigit().

Change-Id: Ide6f5c2f17468bfa953df0961303980fbc6e8956
Reviewed-on: https://pdfium-review.googlesource.com/c/46770
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/fxjs/cjs_util.cpp b/fxjs/cjs_util.cpp
index b30c535..e3948f7 100644
--- a/fxjs/cjs_util.cpp
+++ b/fxjs/cjs_util.cpp
@@ -336,7 +336,7 @@
       } break;
       case '9': {
         if (iSourceIdx < wsSource.GetLength()) {
-          if (std::iswdigit(wsSource[iSourceIdx])) {
+          if (FXSYS_IsDecimalDigit(wsSource[iSourceIdx])) {
             wsResult += wsSource[iSourceIdx];
             ++iFormatIdx;
           }
@@ -421,7 +421,7 @@
       case WIDTH:
         if (c == L'*')
           return -1;
-        if (std::iswdigit(c)) {
+        if (FXSYS_IsDecimalDigit(c)) {
           // Stay in same state.
         } else if (c == L'.') {
           state = PRECISION;
@@ -433,7 +433,7 @@
       case PRECISION:
         if (c == L'*')
           return -1;
-        if (std::iswdigit(c)) {
+        if (FXSYS_IsDecimalDigit(c)) {
           // Stay in same state.
           ++precision_digits;
         } else {