[m-rev.] for possible post-commit objection: remove a ten year old workaround

[Zoltan Somogyi]

We can back it out if this breaks anyone's workflow,
but I don't think that is very likely.

Zoltan.

diff --git a/compiler/make.m b/compiler/make.m
index a7d9ada29..2aaa246d7 100644
--- a/compiler/make.m
+++ b/compiler/make.m
@@ -476,11 +476,7 @@ classify_target(Globals, FileName, ModuleName - TargetType) :-
 
 classify_target_2(Globals, ModuleNameStr0, Suffix, ModuleName - TargetType) :-
     ( if
-        yes(Suffix) = target_extension(Globals, ModuleTargetType),
-        % The .cs extension was used to build all C target files, but .cs is
-        % also the file name extension for a C# file. The former use is being
-        % migrated over to the .all_cs target but we still accept it for now.
-        Suffix \= ".cs"
+        yes(Suffix) = target_extension(Globals, ModuleTargetType)
     then
         ModuleNameStr = ModuleNameStr0,
         TargetType = module_target(ModuleTargetType)