Use _ instead of $ on Windows to avoid shell expansion issues. 

Fixes #2342.

--
Change-Id: I4e6511a5d65a534757bdb6b4b05c9e1bd43ad2d8
Reviewed-on: https://cr.bazel.build/8093
PiperOrigin-RevId: 143695463
MOS_MIGRATED_REVID=143695463

src/main/cpp/blaze_util_windows.cc

diff --git a/src/main/cpp/blaze_util_windows.cc b/src/main/cpp/blaze_util_windows.cc
index f7bf757..ad490d8 100644
--- a/src/main/cpp/blaze_util_windows.cc
+++ b/src/main/cpp/blaze_util_windows.cc
@@ -1056,7 +1056,7 @@
 
   static const char* alphabet
       // Exactly 64 characters.
-      = "abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ0123456789$-";
+      = "abcdefghigklmnopqrstuvwxyzABCDEFGHIGKLMNOPQRSTUVWXYZ0123456789_-";
 
   // The length of the resulting filename (8 characters).
   static const int filename_length = blaze_util::Md5Digest::kDigestLength / 2;