test/lang: absorb retired-carrier coverage

local_zeroinit_test.ww takes the 840/944 zero-init seam (dirty-frame
prime and probe share one @test because the runtime forks per test);
alias_cgen_b6, alloc_nested_field, array_static_init, and
strarray_static gain the rows their retired wrappers held; the
remaining files re-point reject-row citations at the r788_* and
stage-matrix fixtures.

test/lang/array_static_init_test.ww

@@ -11,12 +11,18 @@
 // array-field elements directly (D1.buf[k], D2.m[i][j]): the old #137/#150 cs≠ww
 // global-struct-field-base bug is CLOSED at HEAD, so the read is now cs==ww IDENT
 // — the original deferred this to byte-id only because the bug was then open.
+// The under-length and `...` rows distinguish the two scalar-tail policies:
+// ordinary omitted slots are zero, while an explicit repeat marker replays the
+// last value. Every slot is asserted independently so neither policy can mask
+// the other through a sum.
 
 package array_static_init_test;
 
 let A_U8: [4]u8 = [1u8, 2u8, 3u8, 4u8];
 let A_U32: [4]u32 = [1u32, 2u32, 3u32, 4u32];
 let A_U64: [2]u64 = [1u64, 2u64];
+let A_U64_TAIL: [4]u64 = [1, 2];
+let A_U64_REPEAT: [4]u64 = [7, 9...];
 let A_INEG: [4]i32 = [-1, -2, -3, -4];
 let A_F64: [4]f64 = [1.5, -2.5, 3.5, -4.5];
 let A_F32: [4]f32 = [1.5f32, -2.5f32, 3.5f32, -4.5f32];
@@ -53,6 +59,21 @@ fn at(i: i32, j: i32) u64 = { return A2V[i][j]; };
 @test fn let_u8_arr() void = { assert(A_U8[0]: i32 == 1); };
 @test fn let_u32_arr() void = { assert(A_U32[0]: i32 == 1); };
 @test fn let_u64_arr() void = { assert(A_U64[0]: i32 == 1); };
+
+@test fn let_u64_zero_tail() void = {
+	assert(A_U64_TAIL[0] == 1u64);
+	assert(A_U64_TAIL[1] == 2u64);
+	assert(A_U64_TAIL[2] == 0u64);
+	assert(A_U64_TAIL[3] == 0u64);
+};
+
+@test fn let_u64_repeat_tail() void = {
+	assert(A_U64_REPEAT[0] == 7u64);
+	assert(A_U64_REPEAT[1] == 9u64);
+	assert(A_U64_REPEAT[2] == 9u64);
+	assert(A_U64_REPEAT[3] == 9u64);
+};
+
 @test fn let_i32_neg_arr() void = { assert(A_INEG[0] == -1); };
 
 @test fn let_f64_arr() void = {