Release 3.4, 2018-09-17

Bug fixing:

Redefinition of a typedef in a different scope was wrongly rejected.
Attach _Alignas(N) and __attribute((aligned(N))) to names instead of types, so that _Alignas(16) int * p means "16-aligned pointer to int", not "pointer to 16-aligned int".
For packed structs, fix a discrepancy between the size and alignment computed during elaboration and those computed by the verified front-end after expansion.
Honor qualified array types in function parameters: if a parameter is declared as e.g. int t[const 4], it is now treated as int * const t in the function body, not int * t like before.
Reject __builtin_offsetof(struct s, f) if f is a bit-field.
Wrong parsing of attributes having multiple arguments such as __attribute((packed(A,B,C))).
If __builtin_ais_annot is followed immediately by a label (e.g. a loop head), add a nop instruction to separate the annotation from the label.
Wrong parsing of the command-line options -u <symbol> and -iquote.
PowerPC in hybrid 32/64 bit mode: reject %Q and %R register specifications in inline assembly code, since 64-bit integer arguments are not split in two registers.
x86 64-bit mode: wrong expansion of __builtin_clzl and __builtin_ctzl (issue #127).

Removed support for _Alignof(expr), which is not C11; only _Alignof(ty) is part of C11.
Reject occurrences of _Alignas in places that are not allowed by C11, e.g. in typedef. __attribute((aligned(N))) can be used instead.
Reject occurrences of restrict in places that are not allowed by C99 and C11.
Reject structs composed of a single flexible array struct { ty []; }.
Check that qualified array types such as int t[const 4] occur only as function parameters, but nowhere else.
In function definitions, reject function parameters that have no names.

Warn for flexible array types ty[] in places where they do not make sense.
Warn for inline (not static inline) functions that declare non-constant static variables.
Optionally warn if the alignment of an object is reduced below its natural alignment because of a _Alignas qualifier or an aligned attribute, or a packed attribute.
Warn for tentative static definitions with an incomplete type, e.g. static int x[];.
The warning about uses of C11 features is now off by default.

Model the fact that external functions can destroy caller-save registers and Outgoing stack slots; adapt the proofs accordingly.