Allow the Thrift compiler to be built without the OCaml generator.

- Use AX_THRIFT_GEN to make configure support --disable-gen-ocaml
- Update the compiler Makefile.am to exclude the generator.


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665593 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/Makefile.am b/compiler/cpp/Makefile.am
index eed2043..bb78b1e 100644
--- a/compiler/cpp/Makefile.am
+++ b/compiler/cpp/Makefile.am
@@ -14,7 +14,6 @@
                  src/generate/t_rb_generator.cc \
                  src/generate/t_xsd_generator.cc \
                  src/generate/t_perl_generator.cc \
-                 src/generate/t_ocaml_generator.cc \
                  src/generate/t_erl_generator.cc \
                  src/generate/t_hs_generator.cc \
                  src/generate/t_cocoa_generator.cc \
@@ -61,6 +60,9 @@
 if THRIFT_GEN_java
 thrift_SOURCES += src/generate/t_java_generator.cc
 endif
+if THRIFT_GEN_ocaml
+thrift_SOURCES += src/generate/t_ocaml_generator.cc
+endif
 
 thrift_CXXFLAGS = -Wall -I$(srcdir)/src $(BOOST_CPPFLAGS)
 thrift_LDFLAGS = -Wall $(BOOST_LDFLAGS)