Final bit of type system cleanup that abstracts declaration contexts into lldb_private::CompilerDeclContext and renames ClangType to CompilerType in many accessors and functions.
Create a new "lldb_private::CompilerDeclContext" class that will replace all direct uses of "clang::DeclContext" when used in compiler agnostic code, yet still allow for conversion to clang::DeclContext subclasses by clang specific code. This completes the abstraction of type parsing by removing all "clang::" references from the SymbolFileDWARF. The new "lldb_private::CompilerDeclContext" class abstracts decl contexts found in compiler type systems so they can be used in internal API calls. The TypeSystem is required to support CompilerDeclContexts with new pure virtual functions that start with "DeclContext" in the member function names. Converted all code that used lldb_private::ClangNamespaceDecl over to use the new CompilerDeclContext class and removed the ClangNamespaceDecl.cpp and ClangNamespaceDecl.h files.
Removed direct use of clang APIs from SBType and now use the abstract type systems to correctly explore types.
Bulk renames for things that used to return a ClangASTType which is now CompilerType:
"Type::GetClangFullType()" to "Type::GetFullCompilerType()" "Type::GetClangLayoutType()" to "Type::GetLayoutCompilerType()" "Type::GetClangForwardType()" to "Type::GetForwardCompilerType()" "Value::GetClangType()" to "Value::GetCompilerType()" "Value::SetClangType (const CompilerType &)" to "Value::SetCompilerType (const CompilerType &)" "ValueObject::GetClangType ()" to "ValueObject::GetCompilerType()" many more renames that are similar.