Fix building on Windows in UNICODE mode
diff --git a/src/disk_interface.cc b/src/disk_interface.cc
index e73d901..e64bb43 100644
--- a/src/disk_interface.cc
+++ b/src/disk_interface.cc
@@ -267,7 +267,7 @@
 
 int RealDiskInterface::RemoveFile(const string& path) {
 #ifdef _WIN32
-  DWORD attributes = GetFileAttributes(path.c_str());
+  DWORD attributes = GetFileAttributesA(path.c_str());
   if (attributes == INVALID_FILE_ATTRIBUTES) {
     DWORD win_err = GetLastError();
     if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND) {
@@ -278,7 +278,7 @@
     // On Windows Ninja should behave the same:
     //   https://github.com/ninja-build/ninja/issues/1886
     // Skip error checking.  If this fails, accept whatever happens below.
-    SetFileAttributes(path.c_str(), attributes & ~FILE_ATTRIBUTE_READONLY);
+    SetFileAttributesA(path.c_str(), attributes & ~FILE_ATTRIBUTE_READONLY);
   }
   if (attributes & FILE_ATTRIBUTE_DIRECTORY) {
     // remove() deletes both files and directories. On Windows we have to 
@@ -286,7 +286,7 @@
     // used on a directory)
     // This fixes the behavior of ninja -t clean in some cases
     // https://github.com/ninja-build/ninja/issues/828
-    if (!RemoveDirectory(path.c_str())) {
+    if (!RemoveDirectoryA(path.c_str())) {
       DWORD win_err = GetLastError();
       if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND) {
         return 1;
@@ -296,7 +296,7 @@
       return -1;
     }
   } else {
-    if (!DeleteFile(path.c_str())) {
+    if (!DeleteFileA(path.c_str())) {
       DWORD win_err = GetLastError();
       if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND) {
         return 1;