crt: Need a position-independent CRT for PIE
- Implement the greatest possible part of the crt1 in C
- Implement SPARC versions of the ASM sections of crt1
- Build crt1 position-independently, minor ASM updates to be position
  independent
- Implement crt1 with the hook expected by modern GCC to support
  profiling, make gcrt1 a symlink for source compatibility (older GCC
  initializes profiling at firsnt use of _mcount if necessary, so
  doesn't need the gcrt)
- Split the CRT out of developer/library/lint into a separate c-runtime package

*** 45,55 ****
  
  P_ASOBJS=       boot.o          boot_elf.o      caller.o
  
  S_ASOBJS=       boot_a.out.o
  
! CRTSRCS=        ../../../../lib/common/sparc
  CRTI=           pics/crti.o
  CRTN=           pics/crtn.o
  CRTS=           $(CRTI)         $(CRTN)
  
  CHKSRCS=        $(SRCBASE)/uts/common/krtld/reloc.h
--- 45,55 ----
  
  P_ASOBJS=       boot.o          boot_elf.o      caller.o
  
  S_ASOBJS=       boot_a.out.o
  
! CRTSRCS=        ../../../../lib/crt/sparcv7
  CRTI=           pics/crti.o
  CRTN=           pics/crtn.o
  CRTS=           $(CRTI)         $(CRTN)
  
  CHKSRCS=        $(SRCBASE)/uts/common/krtld/reloc.h