test(C3.3): #define/#flags reach a unit consumed only by hand-curated #foreign decls

examples/1622-cimport-unit-bound-defines.sx

@@ -0,0 +1,17 @@
+// `#define`/`#flags` reach a unit whose ONLY consumer is hand-curated
+// `#foreign` decls (PLAN-C C3.3) — no `#include`, no auto-synthesis:
+// the macro decides what the unit-bound decl answers.
+#import "modules/std.sx";
+
+unit :: #import c {
+    #define "UNIT_BASE=33";
+    #flags  "-O2";
+    #source "1622-cimport-unit-bound-defines/unit.c";
+};
+
+unit_answer :: () -> i32 #foreign unit "unit_answer";
+
+main :: () -> i32 {
+    print("unit answer = {}\n", unit_answer());
+    0
+}

examples/1622-cimport-unit-bound-defines/unit.c

@@ -0,0 +1,4 @@
+#ifndef UNIT_BASE
+#define UNIT_BASE 1
+#endif
+int unit_answer(void) { return UNIT_BASE; }

examples/expected/1622-cimport-unit-bound-defines.exit

@@ -0,0 +1 @@
+0

examples/expected/1622-cimport-unit-bound-defines.stdout

@@ -0,0 +1 @@
+unit answer = 33