• Makefile: . Add s_erfl.c to building libm. . Add MLINKS for erfl.3 and erfcl.3.

• Symbol.map: . Move erfl and erfcl to their proper location.

• ld128/s_erfl.c: . Implementations of erfl and erfcl in the IEEE 754 128-bit format.

• ld80/s_erfl.c: . Implementations of erfl and erfcl in the Intel 80-bit format.

• man/erf.3: . Document the new functions. . While here, remove an incomplete sentence.

• src/imprecise.c: . Remove the stupidity of mapping erfl and erfcl to erf and erfc.

• src/math.h: . Move the declarations of erfl and erfcl to their proper place.

• src/s_erf.c: . For architectures where double and long double are the same floating point format, use weak references to map erfl to erf and ercl to erfc.

Reviewed by: bde (many earlier versions)