Use MODULE_NAME in stap-probe instead of IN_LIB

Use MODULE_NAME in stap-probe instead of IN_LIB

Define MODULE_NAME in the build command and define IN_MODULE using
MODULE_NAME.  Verified that the generated code is unchanged on x86_64.

	* Makeconfig (module-cppflags-real): Define MODULE_NAME
	instead of IN_MODULE.
	* include/libc-symbols.h (IN_MODULE): Define using
	MODULE_NAME.
	(PASTE_NAME, PASTE_NAME1): New macros.
	* include/stap-probe.h (LIBC_PROBE_1): Use MODULE_NAME instead
	of IN_LIB.
	(STAP_PROBE_ASM): Likewise.