IC: remember toplevel .emits

tests/ic/mdefconverter.nim

@@ -0,0 +1,2 @@
+
+converter toBool*(x: int): bool = x != 0

tests/ic/memit.nim

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+# Helper for temit.nim: a NON-main module with a module-scope `{.emit.}` that
+# introduces a C macro consumed by an `{.importc, nodecl.}` const. The IC backend
+# reload used to drop top-level emit pragmas — writeToplevelNode wrote them to the
+# by-symbol-index implementation section, where a symbol-less pragma is never
+# reloaded — so the generated C lost the `#define` and failed to compile with
+# "use of undeclared identifier". Mirrors lib/pure/concurrency/cpuinfo.nim's
+# `#include <sys/sysctl.h>` + `CTL_HW`/`HW_NCPU` importc pattern.
+{.emit: """/*TYPESECTION*/
+#define NIM_IC_EMIT_ANSWER 42
+""".}
+
+let icEmitAnswer {.importc: "NIM_IC_EMIT_ANSWER", nodecl.}: cint
+
+proc emitAnswer*(): int = int(icEmitAnswer)

tests/ic/temit.nim

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+# Regression: a module-scope `{.emit.}` in an imported module must survive the
+# `nim ic` backend reload (see memit.nim). Before the fix the dropped `#define`
+# made the generated C fail to compile, so `nim ic` exited non-zero.
+import memit
+
+doAssert emitAnswer() == 42
+echo emitAnswer()