Fix build break on Solaris introduced by r231940

Solaris apparently doesn't have iswblank_l.


Thanks to C Bergstrom for the report!

llvm-svn: 232172
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: f11625d131f90ec605773040f797d3b1596b1f01
diff --git a/src/locale.cpp b/src/locale.cpp
index 797bd05..54a24e6 100644
--- a/src/locale.cpp
+++ b/src/locale.cpp
@@ -1312,8 +1312,10 @@
             if (iswxdigit_l(ch, __l))
                 *vec |= xdigit;
 #endif
+#if !defined(__sun__)
             if (iswblank_l(ch, __l))
                 *vec |= blank;
+#endif
         }
     }
     return low;