fix(parse): ignore errors from alternative production

regression-tests/pure2-bugfix-for-pointer-type-template-argument.cpp2

@@ -0,0 +1 @@
+main: () = std::is_void_v<* i32>;

regression-tests/test-results/pure2-bugfix-for-pointer-type-template-argument.cpp

@@ -0,0 +1,21 @@
+
+#define CPP2_USE_MODULES         Yes
+
+//=== Cpp2 type declarations ====================================================
+
+
+#include "cpp2util.h"
+
+
+
+//=== Cpp2 type definitions and function declarations ===========================
+
+#line 1 "pure2-bugfix-for-pointer-type-template-argument.cpp2"
+auto main() -> int;
+
+
+//=== Cpp2 function definitions =================================================
+
+#line 1 "pure2-bugfix-for-pointer-type-template-argument.cpp2"
+auto main() -> int { std::is_void_v<cpp2::i32*>;  }
+

regression-tests/test-results/pure2-bugfix-for-pointer-type-template-argument.cpp2.output

@@ -0,0 +1,2 @@
+pure2-bugfix-for-pointer-type-template-argument.cpp2... ok (all Cpp2, passes safety checks)
+

source/parse.h

@@ -4828,6 +4828,7 @@ class parser
                 }
                 else if (auto i = type_id()) {
                     term.arg = std::move(i);
+                    errors.clear(); // clear errors from attempting to parse an expression
                 }
                 else {
                     break;