[MC] Support .symver *, *, remove

As a resolution to https://sourceware.org/bugzilla/show_bug.cgi?id=25295 , GNU as
from binutils 2.35 supports the optional third argument for the .symver directive.

'remove' for a non-default version is useful:
`.symver def_v1, def@v1, remove` => def_v1 is not retained in the symbol table.
Previously the user has to strip the original symbol or specify a `local:`
version node in a version script to localize the symbol.

`.symver def, def@@v1, remove` and `.symver def, def@@@v1, remove` are supported
as well, though they are identical to `.symver def, def@@@v1`.

local/hidden are not useful so this patch does not implement them.

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/MC/MCStreamer.cpp b/llvm/lib/MC/MCStreamer.cpp
index afaa570..ee4cce0 100644
--- a/llvm/lib/MC/MCStreamer.cpp
+++ b/llvm/lib/MC/MCStreamer.cpp
@@ -1160,8 +1160,8 @@ void MCStreamer::emitXCOFFRenameDirective(const MCSymbol *Name,
 }
 
 void MCStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
-void MCStreamer::emitELFSymverDirective(StringRef AliasName,
-                                        const MCSymbol *Aliasee) {}
+void MCStreamer::emitELFSymverDirective(const MCSymbol *OriginalSym,
+                                        StringRef Name, bool KeepOriginalSym) {}
 void MCStreamer::emitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
                                        unsigned ByteAlignment) {}
 void MCStreamer::emitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,