[flang] Fix separate MODULE PROCEDURE when binding label exists (#82686)

When a separate module procedure is defined with a MODULE PROCEDURE and
its corresponding interface has a binding label, the compiler was
emitting an error about mismatching binding labels because the binding
label wasn't being copied into the subprogram's definition.

Author: klausler

flang/lib/Semantics/resolve-names.cpp

@@ -4218,7 +4218,12 @@ bool SubprogramVisitor::BeginMpSubprogram(const parser::Name &name) {
     EraseSymbol(name);
     Symbol &newSymbol{MakeSymbol(name, SubprogramDetails{})};
     PushScope(Scope::Kind::Subprogram, &newSymbol);
-    newSymbol.get<SubprogramDetails>().set_moduleInterface(*symbol);
+    auto &newSubprogram{newSymbol.get<SubprogramDetails>()};
+    newSubprogram.set_moduleInterface(*symbol);
+    auto &subprogram{symbol->get<SubprogramDetails>()};
+    if (const auto *name{subprogram.bindName()}) {
+      newSubprogram.set_bindName(std::string{*name});
+    }
     newSymbol.attrs() |= symbol->attrs();
     newSymbol.set(symbol->test(Symbol::Flag::Subroutine)
             ? Symbol::Flag::Subroutine

flang/test/Semantics/separate-mp02.f90

@@ -148,6 +148,8 @@ module subroutine s5() bind(c)
     end
     module subroutine s6() bind(c)
     end
+    module subroutine s7() bind(c, name="s7")
+    end
   end interface
 end
 
@@ -172,6 +174,8 @@ module subroutine s5() bind(c, name=" s5")
   !ERROR: Module subprogram 's6' has binding label 'not_s6' but the corresponding interface body has 's6'
   module subroutine s6() bind(c, name="not_s6")
   end
+  module procedure s7
+  end
 end