Fixed: Compiler now generates correct empty statement after 'if (a);'

Earlier the compiler generated the 'if' without the last ';' when a empty statement is used, with sometimes devastating result. The same if an empty statement was after the 'else'.

I have also added a test case for some different empty statement senarios.
Merge pull request #1984 from mrcarlberg/if-empty-statement

Fixed: Compiler now generates correct empty statement after 'if (a);'