[Decompilation] Fixes to compiler/decompiler for gcommon

[water111]

No description provided.

[coveralls]

Pull Request Test Coverage Report for Build 542004821

• 285 of 364 (78.3%) changed or added relevant lines in 14 files are covered.
• 17 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.3%) to 67.87%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
decompiler/analysis/cfg_builder.cpp	0	1	0.0%
decompiler/analysis/variable_naming.cpp	7	8	87.5%
tools/dgo_unpacker.cpp	0	1	0.0%
test/decompiler/FormRegressionTest.cpp	10	12	83.33%
goalc/compiler/compilation/Math.cpp	21	24	87.5%
decompiler/IR2/AtomicOpForm.cpp	4	8	50.0%
decompiler/IR2/FormStack.cpp	9	13	69.23%
decompiler/IR2/Form.cpp	19	25	76.0%
decompiler/IR2/FormExpressionAnalysis.cpp	196	253	77.47%

Files with Coverage Reduction	New Missed Lines	%
decompiler/IR2/FormStack.cpp	1	73.58%
decompiler/IR2/FormExpressionAnalysis.cpp	16	87.47%

Totals
Change from base Build 541457656:	0.3%
Covered Lines:	27672
Relevant Lines:	40772

---

💛 - Coveralls