Merge pull request #2922 from stan-dev/fix/dump-full-version

Use -dumpfullversion if available in makefiles

Author: rok-cesnovar

make/compiler_flags

@@ -58,7 +58,7 @@ ifneq (,$(findstring g++,$(CXX)))
   CXX_TYPE ?= gcc
 endif
 CXX_TYPE ?= other
-CXX_VERSION :=  $(shell $(CXX) -dumpversion 2>&1)
+CXX_VERSION :=  $(shell $(CXX) -dumpfullversion -dumpversion 2>&1)
 CXX_MAJOR := $(word 1,$(subst ., ,$(CXX_VERSION)))
 CXX_MINOR := $(word 2,$(subst ., ,$(CXX_VERSION)))