typed variable declaration should not stomp on timer variables

[x87]

#32
Skip TIMERA and TIMERB when allocating the next index It happens e.g. when using a lot of custom variables in a mission code.

[x87]

Managing variable buffer overflow (too many local vars).

Precondition:

• If this is GTA 3 or GTA VC
  • limit number of available indexes to 16 (from 0@ to 15@)
  • 16@ and 17@ are reserved for timers.
• if this is SA
  • if this is a regular script
    • limit number of available indexes to 32 (from 0@ to 31@)
    • 32@ and 33@ are reserved for timers.
  • if this is a mission script
    • limit number of available indexes to 990 (from 34@ to 1023@)
    • 32@ and 33@ are reserved for timers.
• if this is SA Mobile
  • if this is a regular script
    • limit number of available indexes to 40 (from 0@ to 39@)
    • 40@ and 41@ are reserved for timers.
  • if this is a mission script
    • limit number of available indexes to 982 (from 42@ to 1023@)
    • 40@ and 41@ are reserved for timers.
• If this is LCS or VCS
  • limit number of available indexes to 96 (from 0@ to 95@)
  • -1@ and -2@ are reserved for timers.

Validation rule:

• if Ranges check is ON
  • and next requested index overruns the buffer (see ranges above)
  • OR the array size is larger than the number of remaining indexes
    • throw an error

[x87]

this validation will be annoying without #145 . however current behavior is even worse, as new declared variables go beyond the limit without any warning (35@, 36@, etc)