fix Issue 13899 - Unwanted warning for pure opApply

Add explicit cast(void) to discard return value of opApply.
Improve StringExp::length() to support transcoding
Handle extending string literal length to the target static array type

Both expression initializers and struct literal arguments should support implicit string lengthen.
fix Issue 13907 - Surrogate pairs in wchar string literal will cause incorrect length match

Stop considering lengthen conversion in StringExp::implicitConvTo().
fix Issue 12092 - Wrong TLS access in PIC code (X86_32)

- Use RI_TYPE_TLS_GD (general dynamic) to access global
  TLS symbols in PIC code.
code sequence for __tls_get_addr calls is incorrect

- It has to use SIB addressing for the LEA instruction
  to make room for linker optimizations.
NOP after the __tls_get_addr call isn't needed
udiv calls for shared libraries
Merge pull request #4224 from MartinNowak/sharedFBSD

udiv calls for shared libraries
Merge pull request #4223 from MartinNowak/fix12092

fix Issue 12092 - Wrong TLS access in PIC code (X86_32)
Merge pull request #4222 from 9rnsr/fix13907

Issue 13907 - Surrogate pairs in wchar string literal will cause incorrect length match
Merge pull request #4221 from 9rnsr/fix13899

Issue 13899 - Unwanted warning for pure opApply