Removed dead code / sizeof check
Runtime sizeof()
Ensure runtime sizeof() uses size_t arithmetic
Move VLA test
Move vla_bad_parse.c
Pull out backend code gen dispatch + dump type tree on error
Fix VLA/array type creation and interning

Previously init_decayed_array would write to the ptr bits of the
type, incorrectly. Also there were a few places that did const_fold()s
of array sizes, whereas we now properly handle VLAs with size-expression
comparisons instead.
type_is_variably_modified() checks the type's children

e.g. int x[2][3][n];
Handle/error on initialised VLAs (including compound literals)
Error on static/global VLAs
Continue-after-error for pointer to incomplete type arith
Check for nested [*] modifiers
Test for arithmetic on pointer to vla
Fix array type creation for non-VLAs vs. VLAs

[*] in prototype, but not in the function definition now works
Multi-dimensional VLA arithmetic e.g., including as parameter
type_cmp() handles VLAs
static variable with variably modified vs. VLA type example
VLA prototype example
VLA-via-NULL addition example
VLA goto and maybe-eval