- cast to i32 for boolean binary expr
- add `-O2` when testing ir.

- bug: Forget to using vmov in LocalRegAllocator.

- allocate all zero glob var to bss section
- memset to zero before setting initial value

- add test/performance to gitignore
- disable compiler printing in test.
- performance_test ouput time to seperate file.

test script reorganize.

- array not ignore default zero.
- expandBinOp may use IP twice.

before 55_sort_test1.sy.

1.	IR 处理local数组初始化没有把空间都清零。
2.	很多调用eabi的指令要写个Pass转换为函数调用，CastInst也还没搞
3.	寄存器分配这边没有注意保存callee saved reg。
4.	指令选择那里还要多注意Float
5.	Putf的vararg传参遇到浮点数，占用两个寄存器或者存内存，用特殊指令。还没处理。
6.	测试代码太大超过32MB的B指令跳转范围。。。
7.	到处都注意多加注释，把注释打通
8.	最好再把栈上哪个位置是什么也保存为map，另外打印一下

Fix bug in prev commit.

instruction selection framework.

bug: plenty bug fixes.

add sylib.c and sylib.h

pass 95_float.sy
bug: allow variable with same name. (scope)
index suffix for local alloca name.
bug: inexact constant float representation in generated LLVM IR.
bug: Cast Node is parent of NonShortLogicExpr.
bug: No type cast in array initval expr.
bug: wrong type when printing logic BinopInst.
bug: Type.equals when o1.dims==null, o2.dims.size()==0

bug: UnaryExpr wrong inst for UnaryOp.NOT.

heavily changed LogicExpr.
bug: numValueNamer recount per function.

LValExpr can return pointer.
add equals to ssa.ds.Type
bug: string literal not strip double quote.
bug: cast to double when vararg.

pass 05_arr_defn4.sy

pass 005-string-literal.c
bug: not check additional vararg. (sematic)