oss-fuzz: Add unit test build

Signed-off-by: Arthur Chan <[email protected]>

Author: arthurscchan

fuzz/build.sh

@@ -5,4 +5,8 @@ $CXX $CFLAGS $CXXFLAGS \
      -c $SRC/fast_float/fuzz/from_chars.cc -o from_chars.o
 
 $CXX $CFLAGS $CXXFLAGS $LIB_FUZZING_ENGINE from_chars.o \
-     -o $OUT/from_chars
+     -o $OUT/from_chars
+
+# Build unit tests
+cmake -DFASTFLOAT_TEST=ON -DCMAKE_EXE_LINKER_FLAGS="-lpthread"
+make