Finishes implementation of PureJavaScriptGenerator

based on D350

Summary:
[Compiler] Implement some literals

• true, false, this,...
• array literals
• includes style corrections

[Compiler] Implement object literals

[Compiler] Add array and object member access

[Compiler] Implement function calls

[Compiler] Implement loops

• local and global for
• local and global for each
• while
• do while

[Compiler] Add some missing expressions

• void, delete, typeof
• unary +,-,!,~
• new
• conditional expression
• nested expression

[Compiler] Add various elements

• RegExp literals
• some source elements
• comma expression
• function expression
• labelled statement
• with statement

[Compiler] Add try-catch-finally

Reviewers: akreuzkamp

Reviewed By: akreuzkamp

Differential Revision: https://phabricator.kde.org/D366