[various grammars] Fix targets that fail build

[kaby76]

The following targets fail the build:

• asm/ptx/ptx-isa-1.0 with Cpp: NAN is a symbol conflict for Cpp--apparently now for MacOS.
• ./icon ./lark .sieve ./smtlibv2 ./wavefront with Go target--symbol conflict apparently now with "start" as a parser rule.
• ./scala with Go target--timeout. This grammar is super slow. Go target should be removed from desc.xml to indicate it doesn't work.
• elixir with PHP target--stack overflow. The PHP has logical errors in the code. I tried to address some of the problems, but it was too much, and needed to work on other things. Fix for #12 -- Allowed memory size of 134217728 bytes exhausted. antlr-php-runtime#34