Added aliases for frequently used llvm types

include/dusk/AST/ASTNode.h

include/dusk/AST/ASTPrinter.h

include/dusk/AST/ASTWalker.h

include/dusk/AST/Decl.h

include/dusk/AST/Diagnostics.h

include/dusk/AST/DiagnosticsParse.h

include/dusk/AST/Expr.h

include/dusk/AST/Pattern.h

include/dusk/AST/Stmt.h

include/dusk/Basic/CMakeLists.txt

include/dusk/Basic/LLVM.h

include/dusk/Basic/SourceManager.h

include/dusk/Frontend/Compiler.h

include/dusk/Frontend/Formatter.h

include/dusk/Frontend/InputFile.h

include/dusk/IRGen/CMakeLists.txt

include/dusk/IRGen/Context.h

include/dusk/IRGen/IRGenerator.h

include/dusk/Parse/Lexer.h

include/dusk/Parse/Parser.h