ARM test suite fixes
We don't need a result variable as t->ctype caches the value
Move rmem.h out of frontend headers
Use rmem instead of C malloc in Array::toChars
fix Issue 11941 - Errors when appending to aggregate member array in CTFE
Merge pull request #3112 from 9rnsr/fix11941

[REG2.065a] Issue 11941 - Errors when appending to aggregate member array in CTFE
Merge pull request #3095 from ibuclaw/safe_mem

Move rmem.h out of frontend headers
Merge pull request #3109 from yebblies/toctype2

[refactor] We don't need a result variable as t->ctype caches the value
Merge pull request #3093 from jpf91/arm-1

ARM test suite fixes