Issue 10312 - [CTFE] ICE assigning to const vector decl
Issue 8543 - [CTFE] simd literals need better support
Issue 10905 - [CTFE] Fix [ICE](ctfeexpr.c line 355) with ulong2 in structs
Merge pull request #2913 from ibuclaw/issue8543

Issue 8543 - [CTFE] simd literals need better support
Merge pull request #2914 from ibuclaw/issue10312

Issue 10312 - [CTFE] ICE assigning to const vector decl
Merge pull request #2937 from ibuclaw/issue10905

Issue 10905 - [CTFE] Fix [ICE](ctfeexpr.c line 355) with ulong2 in structs
Fix clang warnings.

This pull request fixes some simple warnings which clang emits:
- mismatch between class and struct declaration
- mismatch between unsigned type and signed value
- missing virtual destructor