Add option to suppress versioning of the internal name

exports/Makefile

@@ -132,8 +132,12 @@ libgoto_hpl.def : $(GENSYM)
 	./$(GENSYM) win2khpl $(ARCH) dummy $(EXPRECISION) $(NO_CBLAS) $(NO_LAPACK) $(NO_LAPACKE) $(NEED2UNDERSCORES) $(ONLY_CBLAS) "$(SYMBOLPREFIX)" "$(SYMBOLSUFFIX)" $(BUILD_LAPACK_DEPRECATED) $(BUILD_BFLOAT16) $(BUILD_SINGLE) $(BUILD_DOUBLE) $(BUILD_COMPLEX) $(BUILD_COMPLEX16) > $(@F)
 
 ifeq ($(OSNAME), Darwin)
+ifeq ($(FIXED_LIBNAME),1)
+INTERNALNAME = $(LIBPREFIX).dylib
+else
 INTERNALNAME = $(LIBPREFIX).$(MAJOR_VERSION).dylib
 endif
+endif
 
 ifeq (, $(SYMBOLPREFIX)$(SYMBOLSUFFIX))
 $(LIBDYNNAME) : ../$(LIBNAME) osx.def
@@ -169,8 +173,12 @@ INTERNALNAME = $(LIBPREFIX).so
 FEXTRALIB += -lm
 EXTRALIB += -lm
 else
+ifeq ($(FIXED_LIBNAME),1)
+INTERNALNAME = $(LIBPREFIX).so
+else
 INTERNALNAME = $(LIBPREFIX).so.$(MAJOR_VERSION)
 endif
+endif
 
 ifeq (, $(SYMBOLPREFIX)$(SYMBOLSUFFIX))
 ../$(LIBSONAME) : ../$(LIBNAME) linktest.c