Remove unused declarations.

Bug: http://b/298741930
Test: treehugger
Change-Id: I5a26cf7c9a14748976b16434a127949f1478bdff
diff --git a/linker/linker.h b/linker/linker.h
index a803424..e42876a 100644
--- a/linker/linker.h
+++ b/linker/linker.h
@@ -103,10 +103,6 @@
 
 int do_dladdr(const void* addr, Dl_info* info);
 
-// void ___cfi_slowpath(uint64_t CallSiteTypeId, void *Ptr, void *Ret);
-// void ___cfi_slowpath_diag(uint64_t CallSiteTypeId, void *Ptr, void *DiagData, void *Ret);
-void ___cfi_fail(uint64_t CallSiteTypeId, void* Ptr, void *DiagData, void *Ret);
-
 void set_application_target_sdk_version(int target);
 int get_application_target_sdk_version();