Scope of Use Clauses - Can Use Clause Hide a previous use clause?

I have the following code that produces the same effects in two different tools:

package gen_pkg is 
  generic ( W : natural );

  constant CONST    : natural := W;
end package gen_pkg;



entity name_clash is
end entity name_clash;

architecture clash of name_clash is
  package pkg is new work.gen_pkg generic map( 8 );    
  use pkg.all;

begin

  p: process
    package pkg is new work.gen_pkg generic map( 9 );
    use pkg.all;
  begin
    report to_string(CONST);
    wait;
  end process;

end architecture;

Here a package is declared and used in the architecture. Another package with the same name is declared and used in process p

Two different tools have different behaviors that may both be legal WRT the LRM.

Aldec:

Compile Package "gen_pkg"
Compile Entity "name_clash"
Compile Architecture "clash" of Entity "name_clash"
Error: COMP96_0419: name_clash.vhd : (22, 22): Ambiguous reference to "CONST". Visible declarations include 'clash.pkg.CONST' and 'clash.pkg.CONST'.

GHDL:

PS C:\Temp> ghdl.exe -a --std=08 "C:\msys64\home\Patrick Lehmann\temp\trickyhead.vhdl"
C:\msys64\home\Patrick Lehmann\temp\trickyhead.vhdl:19:13:warning: declaration of "pkg" hides instantiation package "pkg" [-Whide]
    package pkg is new work.gen_pkg generic map( 9 );
            ^
C:\msys64\home\Patrick Lehmann\temp\trickyhead.vhdl:22:22: no declaration for "const" (due to conflicts)
    report to_string(CONST);
                     ^
C:\msys64\mingw64\bin\ghdl.exe: compilation error

So Aldec is reporting a name clash on CONST by including both packages in the process. While GHDL is replacing the pkg instance inside the process scope with a new package.

I cannot find a reference in the LRM to specify which behaviour is correct.