*: fix bugs and add bootstrap test

[tiancaiamao]

• fix closure convert in lib/compile.cora, for case '(let #val2 42 (lambda () (cons #val2 (lambda () 111))))
• add back more builtin functions like 'load' and 'import' etc
• fix reader printObj function
• fix the malloc of call stack size and eval stack size (they should be sz*sizeof(struct XX))
• add test case for bootstrap, cd src; make bootstrap_test to run it.

Now the compile.bc and init.bc is generated from the test, which indicate the code is much more mature