[Support] Use FILE_SHARE_DELETE to fix RemoveFileOnSignal on Windows

Summary:
Tools like clang that use RemoveFileOnSignal on their output files
weren't actually able to clean up their outputs before this change.  Now
the call to llvm::sys::fs::remove succeeds and the temporary file is
deleted. This is a stop-gap to fix clang before implementing the
solution outlined in PR34070.

Reviewers: davide

Subscribers: llvm-commits, hiraditya

Differential Revision: https://reviews.llvm.org/D36337

llvm-svn: 310137
diff --git a/llvm/lib/Support/Windows/Path.inc b/llvm/lib/Support/Windows/Path.inc
index 60c0364..8dac0e4 100644
--- a/llvm/lib/Support/Windows/Path.inc
+++ b/llvm/lib/Support/Windows/Path.inc
@@ -925,9 +925,10 @@
   if (Flags & F_RW)
     Access |= GENERIC_READ;
 
-  HANDLE H = ::CreateFileW(PathUTF16.begin(), Access,
-                           FILE_SHARE_READ | FILE_SHARE_WRITE, NULL,
-                           CreationDisposition, FILE_ATTRIBUTE_NORMAL, NULL);
+  HANDLE H =
+      ::CreateFileW(PathUTF16.begin(), Access,
+                    FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+                    NULL, CreationDisposition, FILE_ATTRIBUTE_NORMAL, NULL);
 
   if (H == INVALID_HANDLE_VALUE) {
     DWORD LastError = ::GetLastError();