first commit
comment support
triple
switch case
repeat-until
Add        decaf/error/UntermCommentError.java
Add        .gitignore
init commit
Merge commit '9b218f0a722d6b40e8fe50888f67471474a6fd4c'

Conflicts:
	decaf/Driver.java
	decaf/Location.java
	decaf/Option.java
	decaf/frontend/BaseParser.java
	decaf/tree/Tree.java
Merge remote-tracking branch 'remotes/origin/master'
add type ck
complete switch case
build symbol
fix lvalue error
Merge commit 'ed9166f060a8fa49b45cb9ed0574aba9c3fdd7cb' into PA3

Conflicts:
	decaf/Driver.java
	decaf/Location.java
	decaf/Option.java
	decaf/frontend/BaseParser.java
	decaf/frontend/Lexer.java
	decaf/symbol/Class.java
	decaf/symbol/Function.java
	decaf/symbol/Variable.java
	decaf/tree/Tree.java
Merge branch 'master' into PA3

Conflicts:
	decaf/frontend/Lexer.java
fix opStr error in regression testing
remove vtable parent
TAC for Repeat-Until loop
tac for triple operator