astgen: blockExpr rvalue, local_ptr rvalue, array_mult

- blockExpr: call rvalue on void result for unlabeled blocks, matching
  upstream AstGen.zig:2431. This was causing a missing STORE_NODE when
  empty blocks like {} were used as struct field values with pointer RL.
- identifierExpr: call rvalueNoCoercePreRef after LOAD in local_ptr case,
  matching upstream AstGen.zig:8453-8454.
- Implement AST_NODE_ARRAY_MULT (** operator) with ArrayMul payload,
  matching upstream AstGen.zig:774-785.
- Enable parser_test.zig and astgen_test.zig corpus tests.
- Enable combined corpus test (all 5 files pass).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

stage0/astgen.c

@@ -2480,6 +2480,7 @@ static uint32_t tryResolvePrimitiveIdent(GenZir* gz, uint32_t node);
 #define COMPTIME_REASON_ADDRSPACE 51
 #define COMPTIME_REASON_FIELD_NAME 42
 #define COMPTIME_REASON_COMPTIME_KEYWORD 53
+#define COMPTIME_REASON_ARRAY_MUL_FACTOR 22
 #define COMPTIME_REASON_SWITCH_ITEM 56
 #define COMPTIME_REASON_TUPLE_FIELD_DEFAULT_VALUE 57
 
@@ -3100,7 +3101,8 @@ static uint32_t identifierExpr(
             if (lp->name == name_str) {
                 if (RL_IS_REF(rl))
                     return lp->ptr;
-                return addUnNode(gz, ZIR_INST_LOAD, lp->ptr, node);
+                uint32_t val = addUnNode(gz, ZIR_INST_LOAD, lp->ptr, node);
+                return rvalueNoCoercePreRef(gz, rl, val, node);
             }
             s = lp->parent;
             continue;
@@ -4590,6 +4592,20 @@ static uint32_t exprRl(GenZir* gz, Scope* scope, ResultLoc rl, uint32_t node) {
     case AST_NODE_ARRAY_CAT:
         return rvalue(
             gz, rl, simpleBinOp(gz, scope, node, ZIR_INST_ARRAY_CAT), node);
+    // array_mult (AstGen.zig:774-785): ** binary operator.
+    case AST_NODE_ARRAY_MULT: {
+        uint32_t res_ty = rlResultType(gz, rl, node);
+        uint32_t lhs = exprRl(gz, scope, RL_NONE_VAL, nd.lhs);
+        ResultLoc rhs_rl = { .tag = RL_COERCED_TY,
+            .data = ZIR_REF_USIZE_TYPE,
+            .src_node = 0,
+            .ctx = 0 };
+        uint32_t rhs = comptimeExpr(
+            gz, scope, rhs_rl, nd.rhs, COMPTIME_REASON_ARRAY_MUL_FACTOR);
+        uint32_t result = addPlNodeTriple(gz, ZIR_INST_ARRAY_MUL, node,
+            res_ty != 0 ? res_ty : ZIR_REF_NONE, lhs, rhs);
+        return rvalue(gz, rl, result, node);
+    }
     // grouped_expression (AstGen.zig:1100): passthrough.
     case AST_NODE_GROUPED_EXPRESSION:
         return exprRl(gz, scope, rl, ag->tree->nodes.datas[node].lhs);
@@ -5386,7 +5402,6 @@ static uint32_t expr(GenZir* gz, Scope* scope, uint32_t node) {
 
 static uint32_t blockExprExpr(
     GenZir* gz, Scope* scope, ResultLoc rl, uint32_t node) {
-    (void)rl;
     AstGenCtx* ag = gz->astgen;
     const Ast* tree = ag->tree;
     AstNodeTag tag = tree->nodes.tags[node];
@@ -5459,7 +5474,8 @@ static uint32_t blockExprExpr(
             GenZir sub_gz = makeSubBlock(gz, scope);
             blockExprStmts(&sub_gz, &sub_gz.base, statements, stmt_count);
         }
-        return ZIR_REF_VOID_VALUE;
+        // AstGen.zig:2431
+        return rvalue(gz, rl, ZIR_REF_VOID_VALUE, node);
     }
 
     // Labeled block (AstGen.zig:2466-2536).

stage0/astgen_test.zig

@@ -256,6 +256,32 @@ fn expectEqualZir(gpa: Allocator, ref: Zir, got: c.Zir) !void {
                     @as(i32, @intCast(got_counts[t])) - @as(i32, @intCast(ref_counts[t])),
                 });
         }
+        // Find first tag divergence.
+        const min_len = @min(ref_len, got.inst_len);
+        for (0..min_len) |i| {
+            const ref_tag: u8 = @intFromEnum(ref_tags[i]);
+            const got_tag: u8 = @intCast(got.inst_tags[i]);
+            if (ref_tag != got_tag) {
+                std.debug.print("first divergence at [{d}]: ref_tag={d} got_tag={d}\n", .{ i, ref_tag, got_tag });
+                // Show ref instruction data for this position.
+                const rd = ref_datas[i];
+                std.debug.print("  ref pl_node: src_node={d} payload={d}\n", .{
+                    rd.pl_node.src_node, rd.pl_node.payload_index,
+                });
+                // Scan for nearest declaration.
+                var j: usize = i;
+                while (j > 0) {
+                    j -= 1;
+                    if (ref_tags[j] == .declaration) {
+                        std.debug.print("  nearest decl at [{d}]: src_node={d}\n", .{
+                            j, ref_datas[j].declaration.src_node,
+                        });
+                        break;
+                    }
+                }
+                break;
+            }
+        }
         return error.TestExpectedEqual;
     }
 
@@ -817,9 +843,6 @@ test "astgen: corpus tokenizer_test.zig" {
 }
 
 test "astgen: corpus parser_test.zig" {
-    // TODO: 10+ extra data mismatches (ref=48 got=32, bit 4 = propagate_error_trace)
-    // in call instruction flags — ctx propagation differs from upstream.
-    if (true) return error.SkipZigTest;
     const gpa = std.testing.allocator;
     try corpusCheck(gpa, @embedFile("parser_test.zig"));
 }
@@ -857,7 +880,7 @@ test "astgen: struct init typed" {
 }
 
 test "astgen: corpus" {
-    if (true) return error.SkipZigTest; // TODO: parser_test.zig fails
+    // All individual corpus tests now pass.
     const gpa = std.testing.allocator;
 
     var any_fail = false;