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

@@ -41,11 +41,11 @@
 # interdependencies" below.
 .PARALLEL:
 
 # Build libc and its dependencies
 SUBDIRS=                        \
-        common                  \
+        crt                     \
         ../cmd/sgs/libconv      \
         ../cmd/sgs/libdl        \
         libc                    \
         .WAIT
 

@@ -548,12 +548,12 @@
 _msg:                   $(MSGSUBDIRS:%=%-nodepend) .WAIT _dc
 
 _dc:                    $(DCSUBDIRS:%=%-nodepend)
 
 # Library interdependencies are called out explicitly here.
-../cmd/sgs/libconv: common
-../cmd/sgs/libdl: common
+../cmd/sgs/libconv: crt
+../cmd/sgs/libdl: crt
 libc:           ../cmd/sgs/libconv ../cmd/sgs/libdl
 
 libm:           libc
 libmd:          libc
 libmp:          libc