optimize memory allocations

[dkropachev]

Gemini code is not optimized for memory allocations. Here is what we can do as first step to optimize it:

1. Locate most loaded peaces of the code:

• Value generator
• Statements builder
• Test status submitting/consuming

2. Optimize them with following in the mind:

• Use pointer for: structs and strings
• Reuse what could be reused
• Get rid of excess operations