fix(ir): value-param type functions + range-checked dim/lane fold (0083, 0087)

Two remaining siblings in F0.4's comptime-int path.

1. Type-returning function with a value param used as a TYPE annotation
   (`b : Make(N, s64)` where `Make :: ($K: u32, $T: Type) -> Type`):
   - `isValueParamPosition` (semantic_diagnostics) now also skips a value
     param of a `fn_ast_map` type-returning function, so `N` is not walked
     as the type name "N" ("unknown type 'N'").
   - `resolveParameterizedWithBindings` routes a type-returning-function
     name to `instantiateTypeFunction` (the `.call` path already did).
   - `instantiateTypeFunction` resolves a general return-type expression
     (`return [K]T`) with bindings active — not just struct/union returns.
   `Make(N, s64)`, `Make(M + 1, s64)`, `Make(3, s64)` all resolve to one
   `[3]s64`.

2. Oversized dim/lane fold panicked the compiler (0087): an array dim /
   Vector lane folded to a valid i64 (5e9) then narrowed to u32 with an
   unchecked `@intCast`. New single gate `program_index.foldDimU32` folds
   via `evalConstIntExpr` then range-checks `[min, maxInt(u32)]`; the three
   narrowing sites (resolveArrayLen stateful + stateless, resolveVectorLane)
   all route through it and emit a clean diagnostic + halt instead of
   panicking. Value-param args stay i64 until used as a dim/lane, where the
   same gate checks them.

Regressions: examples/0208 (value-param type function), examples/1130
(oversized array dim clean halt), examples/1503 (oversized Vector lane
clean halt). Marks issue 0087 RESOLVED.

Gate: zig build, zig build test, bash tests/run_examples.sh — 398 passed,
0 failed, 0 timed out.

examples/expected/0208-generics-value-param-type-function.exit

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

examples/expected/0208-generics-value-param-type-function.stderr

@@ -0,0 +1 @@
+

examples/expected/0208-generics-value-param-type-function.stdout

@@ -0,0 +1,3 @@
+named: len=3 a0=10 a2=30
+expr: len=3 e2=9
+copy: len=3 b2=30

examples/expected/1130-diagnostics-array-dim-oversized-u32.exit

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

examples/expected/1130-diagnostics-array-dim-oversized-u32.stderr

@@ -0,0 +1,5 @@
+error: array dimension 5000000000 does not fit in u32
+  --> examples/1130-diagnostics-array-dim-oversized-u32.sx:13:10
+   |
+13 |     a : [5000000000]s64 = ---;
+   |          ^^^^^^^^^^

examples/expected/1130-diagnostics-array-dim-oversized-u32.stdout

@@ -0,0 +1 @@
+

examples/expected/1503-vectors-oversized-lane-not-u32.exit

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

examples/expected/1503-vectors-oversized-lane-not-u32.stderr

@@ -0,0 +1,11 @@
+error: Vector lane count 5000000000 does not fit in u32
+  --> examples/1503-vectors-oversized-lane-not-u32.sx:13:16
+   |
+13 |     v : Vector(5000000000, f32) = ---;
+   |                ^^^^^^^^^^
+
+error: field 'x' not found on type 'unresolved'
+  --> examples/1503-vectors-oversized-lane-not-u32.sx:14:32
+   |
+14 |     print("unreachable: {}\n", v.x);
+   |                                ^^^

examples/expected/1503-vectors-oversized-lane-not-u32.stdout

@@ -0,0 +1 @@
+