Support: Remove F_{None,Text,Append} compatibility synonyms, NFC

[dexonsmith]

Summary

Remove the compatibility spellings of OF_{None,Text,Append} that
were left behind by 1f67a3cba9b09636c56e2109d8a35ae96dc15782.

No functionality change here, just an API cleanup.

[MaskRay]

Perhaps split the migration part from the OpenFlags removal part. I thought about deleting the aliases too but refrained because I noticed our internal code base needs migration.
Since you propose this, I will start migration and hopefully can finish that next week so that you will not be blocked.

[MaskRay]

I've fixed Halide and sent patches for https://github.com/JuliaLang/julia/pull/40666 & https://github.com/rust-lang/rust/pull/84724 & https://github.com/GPUOpen-Drivers/llpc/pull/1232

[dexonsmith]

In D101506#2724746, @MaskRay wrote:

Perhaps split the migration part from the OpenFlags removal part. I thought about deleting the aliases too but refrained because I noticed our internal code base needs migration.
Since you propose this, I will start migration and hopefully can finish that next week so that you will not be blocked.

SGTM; I almost split it up from the beginning, not sure what made me lazy about this time. I'll try to post the split tomorrow.

In D101506#2727306, @MaskRay wrote:

I've fixed Halide and sent patches for https://github.com/JuliaLang/julia/pull/40666 & https://github.com/rust-lang/rust/pull/84724 & https://github.com/GPUOpen-Drivers/llpc/pull/1232

Great! Thanks.

[dexonsmith]

Rebased on top of https://reviews.llvm.org/D101506 -- that updates all in-tree users, and now this is just removing the API.

[MaskRay]

Perhaps give us and other projects one week or longer ...

[dexonsmith]

In D101506#2729839, @MaskRay wrote:

Perhaps give us and other projects one week or longer ...

Sure thing; I'll try committing next week some time.

llvm/include/llvm/Support/FileSystem.h

 
 enum FileAccess : unsigned {
   FA_Read = 1,
   FA_Write = 2,
 };
 
 enum OpenFlags : unsigned {
   OF_None = 0,
-  F_None = 0, // For compatibility
 
   /// The file should be opened in text mode on platforms like z/OS that make
   /// this distinction.
   OF_Text = 1,
-  F_Text = 1, // For compatibility
 
   /// The file should use a carriage linefeed '\r\n'. This flag should only be
   /// used with OF_Text. Only makes a difference on Windows.
   OF_CRLF = 2,
 
   /// The file should be opened in text mode and use a carriage linefeed '\r\n'.
   /// This flag has the same functionality as OF_Text on z/OS but adds a
   /// carriage linefeed on Windows.
   OF_TextWithCRLF = OF_Text | OF_CRLF,
 
   /// The file should be opened in append mode.
   OF_Append = 4,
-  F_Append = 4, // For compatibility
 
   /// Delete the file on close. Only makes a difference on windows.
   OF_Delete = 8,
 
   /// When a child process is launched, this file should remain open in the
   /// child process.
   OF_ChildInherit = 16,