Fix about 12 kinds of warnings over the codebase

This change fixes:
1) Member initiazalization order in class constructor didn't correspond to the member order in some classes
2) Objects with vtables were copied via memcpy. While this is intentional, cast of the pointers to void*
is required to silence clang warning
3) Switch case statements containing values of different enums
4) Casting int to pointer
5) Missing return value in methods with _ASSERTE
6) Class name classifier on methods in the .h
7) Invalid position of the DECLSPEC_ALIGN at few places - it had no effect
8) Invalid position of the 'used' attribute
9) Issue with comparing holders to NULL
10) Operator 'new' returning NULL without being marked with throw() or noexcept
11) Variables marked as 'extern' at the declaration / initialization place
12) Data structure declared as struct at one place and forward declared as class at another

Some disabled warnings were no longer happening, so options to disable them were removed too

1 files changed, 2 insertions, 2 deletions

diff --git a/src/vm/ilstubresolver.cpp b/src/vm/ilstubresolver.cpp
index 5c717d7805..2f872bbeb8 100644
--- a/src/vm/ilstubresolver.cpp
+++ b/src/vm/ilstubresolver.cpp
@@ -296,8 +296,8 @@ MethodDesc* ILStubResolver::GetStubMethodDesc()
 
 ILStubResolver::ILStubResolver() : 
     m_pCompileTimeState(dac_cast<PTR_CompileTimeState>(ILNotYetGenerated)),
-    m_pStubMD(dac_cast<PTR_MethodDesc>(NULL)),
-    m_pStubTargetMD(dac_cast<PTR_MethodDesc>(NULL)),
+    m_pStubMD(dac_cast<PTR_MethodDesc>(nullptr)),
+    m_pStubTargetMD(dac_cast<PTR_MethodDesc>(nullptr)),
     m_type(Unassigned),
     m_dwJitFlags(0)
 {