test: migrate 700_e2e rows to corpus fixtures; retire the carrier

136 rows migrated, 0 already owned, 3 wwstage-failing rows held out.

test/wcc/data/r700_args9_spill/case.ww

@@ -0,0 +1,7 @@
+//ww:run-exit 45
+// Migrated from 700_e2e row 12.
+package main;
+fn s9(a: i32, b: i32, c: i32, d: i32, e: i32, f: i32, g: i32, h: i32, i: i32) i32 = {
+  return a + b + c + d + e + f + g + h + i;
+};
+fn main() i32 = { return s9(1,2,3,4,5,6,7,8,9); };