Fix parsing of external name in concurrent signal assignment

Fixes #1156

NEWS.md

@@ -2,7 +2,9 @@
 - Fixed invalid LLVM IR generation which could cause a crash with LLVM
   14 (#1145).
 - Functional coverage is now reported correctly when summing from nested
-  hierarchies
+  hierarchies (#1154).
+- External names can now be the target of concurrent signal assignment
+  statements (#1156).
 
 ## Version 1.15.1 - 2025-01-22
 - Fixed a crash when a subprogram is called with too many named arguments

src/parse.c

@@ -13202,6 +13202,7 @@ static tree_t p_concurrent_statement(void)
       return p_generate_statement(label);
 
    case tLPAREN:
+   case tLTLT:
       return p_concurrent_signal_assignment_statement(label, NULL);
 
    case tID:
@@ -13259,7 +13260,8 @@ static tree_t p_concurrent_statement(void)
       }
    default:
       expect(tPROCESS, tPOSTPONED, tCOMPONENT, tENTITY, tCONFIGURATION,
-             tWITH, tASSERT, tBLOCK, tIF, tFOR, tCASE, tLPAREN, tID);
+             tWITH, tASSERT, tBLOCK, tIF, tFOR, tCASE, tLPAREN, tID,
+             STD(08, tLTLT));
       drop_tokens_until(tSEMI);
       return ensure_labelled(tree_new(T_BLOCK), label);
    }

test/sem/ename.vhd

@@ -45,4 +45,6 @@ begin
     begin
     end process;
 
+    << signal ^.foo : bit >> <= '1';    -- OK (issue #1156)
+
 end architecture;