Bug 24733 – ImportC: `#pragma pack(pop)` restores wrong alignment

``` struct S1 {unsigned char c;int i;}; #pragma pack(push, 2) struct S2 {unsigned char c;int i;}; #pragma pack(push, 1) struct S3 {unsigned char c;int i;}; #pragma pack(pop) struct S4 {unsigned char c;int i;}; #pragma pack(pop) struct S5 {unsigned char c;int i;}; _Static_assert(_Alignof(struct S1) == 4, "alignof S1"); _Static_assert(_Alignof(struct S2) == 2, "alignof S2"); _Static_assert(_Alignof(struct S3) == 1, "alignof S3"); _Static_assert(_Alignof(struct S4) == 2, "alignof S4"); // fails _Static_assert(_Alignof(struct S5) == 4, "alignof S5"); _Static_assert(sizeof(struct S1) == 8, "sizeof S1"); _Static_assert(sizeof(struct S2) == 6, "sizeof S2"); _Static_assert(sizeof(struct S3) == 5, "sizeof S3"); _Static_assert(sizeof(struct S4) == 6, "sizeof S4"); // fails _Static_assert(sizeof(struct S5) == 8, "sizeof S5"); ```

@tim-dlang created dlang/dmd pull request #16821 "Fix bugzilla 24733 - ImportC: `#pragma pack(pop)` restores wrong alignment" fixing this issue: - Fix bugzilla 24733 - ImportC: `#pragma pack(pop)` restores wrong alignment https://github.com/dlang/dmd/pull/16821

dlang/dmd pull request #16821 "Fix bugzilla 24733 - ImportC: `#pragma pack(pop)` restores wrong alignment" was merged into master: - 626c0a5ab70f4f79f970157656fa00fc1fd3e722 by Tim Schendekehl: Fix bugzilla 24733 - ImportC: `#pragma pack(pop)` restores wrong alignment https://github.com/dlang/dmd/pull/16821