Add more math and Conditional Branching

[water111]

7 functions down, only 10,423 left!

[coveralls]

Pull Request Test Coverage Report for Build 252831549

• 260 of 341 (76.25%) changed or added relevant lines in 13 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.4%) to 59.093%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
goalc/compiler/Env.cpp	9	10	90.0%
goalc/compiler/Env.h	4	5	80.0%
goalc/compiler/Val.cpp	9	10	90.0%
goalc/compiler/compilation/Atoms.cpp	5	6	83.33%
goalc/main.cpp	0	1	0.0%
goalc/compiler/compilation/Define.cpp	19	23	82.61%
goalc/compiler/compilation/Math.cpp	26	35	74.29%
goalc/compiler/compilation/ControlFlow.cpp	81	108	75.0%
goalc/compiler/IR.cpp	79	115	68.7%

Totals
Change from base Build 252501915:	0.4%
Covered Lines:	12286
Relevant Lines:	20791

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💛 - Coveralls