* config/linux.h (LIB_SPEC): If -pthread, add -lpthread even if
	-shared.
	* config/alpha/linux-elf.h (LIB_SPEC): Likewise.
	* config/alpha/linux.h (LIB_SPEC): Likewise.
	* config/arm/linux-elf.h (LIB_SPEC): Likewise.
	* config/pa/pa-linux.h (LIB_SPEC): Likewise.
	* config/sparc/linux.h (LIB_SPEC): Likewise.
	* config/sparc/linux64.h (LIB_SPEC): Likewise.

From-SVN: r59992