Why are hotspot tests not always linked with libc?

[David Holmes]

In make/test/JtregNativeHotspot.gmk we have this ever expanding list:

ifeq ($(TOOLCHAIN_TYPE), solstudio)
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_liboverflow := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libSimpleClassFileLoadHook := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libGetOwnedMonitorInfoTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libGetNamedModuleTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libIsModifiableModuleTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LDFLAGS_libAddModuleReadsTest := -lc
 
BUILD_HOTSPOT_JTREG_LIBRARIES_LDFLAGS_libAddModuleExportsAndOpensTest := -lc
 
BUILD_HOTSPOT_JTREG_LIBRARIES_LDFLAGS_libAddModuleUsesAndProvidesTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libMAAClassFileLoadHook := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libMAAClassLoadPrepare := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libMAAThreadStart := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libAllowedFunctions := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libRedefineDoubleDelete := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libHandshakeTransitionTest := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libHasNoEntryPoint := -lc
     BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libReturnError := -lc
endif

Why do we need to do this instead of always linking in the basic libraries?

We're investigating a test-image build failure on Solaris x64 slowdebug 
that seems to be caused by implicit use of functions in libc.

Thanks,
David