Add reproducer for issue18.

testsuite/gna/issue18/fum.vhdl

@@ -0,0 +1,55 @@
+package fum is 
+    type fie is protected 
+        impure function foo return integer;
+        impure function foo(input: real) return integer; -- 4
+        impure function foo return integer_vector;
+        impure function foo (input: real) return integer_vector; -- 6
+        impure function foo (input: integer) return integer;
+        impure function foo(input: integer) return integer_vector;
+
+    end protected fie;
+end package;
+
+package body fum is
+    type fie is protected body
+        variable answer:    integer := 42;
+
+        impure function foo return integer is
+        begin
+            return answer;
+        end;
+
+        impure function foo(input:real) return integer is
+        begin
+            return integer(input) + answer;
+        end;
+
+        impure function foo return integer_vector is 
+            variable conv_vector: integer_vector (0 to 1);
+        begin
+            conv_vector(0) := answer;
+            conv_vector(1) := 0;
+            return conv_vector;
+        end; 
+
+        impure function foo (input: real) return integer_vector is
+            variable conv_vector: integer_vector (0 to 1);
+        begin
+            conv_vector(0) := integer(input) + answer;
+            conv_vector(1) := 0;
+        end;
+
+        impure function foo (input: integer) return integer is
+        begin
+            return answer + input;
+        end;
+
+        impure function foo(input: integer) return integer_vector is 
+            variable conv_vector: integer_vector (0 to 1);
+        begin
+            conv_vector(0) := input + answer;
+            conv_vector(1) := 0;
+            return conv_vector;
+        end; 
+    end protected body fie;
+end package body;

testsuite/gna/issue18/integer_ambig.vhdl

@@ -0,0 +1,15 @@
+use work.fum.all;
+
+entity overload_index_issue is
+end entity overload_index_issue ;
+architecture dumbit_down of overload_index_issue is
+    shared variable fee: fie;
+begin
+
+    process
+        variable Data : integer ;
+    begin
+        Data := fee.foo(120.0);
+        wait;
+    end process;
+end architecture dumbit_down;

testsuite/gna/issue18/testsuite.sh

@@ -0,0 +1,12 @@
+#! /bin/sh
+
+. ../../testenv.sh
+
+GHDL_STD_FLAGS=--std=08
+analyze fum.vhdl
+analyze integer_ambig.vhdl
+elab_simulate  overload_index_issue
+
+clean
+
+echo "Test successful"