Add host-f32 config to test MRB_USE_FLOAT32; ref #5329

build_config/host-f32.rb

@@ -0,0 +1,14 @@
+MRuby::Build.new do |conf|
+  # load specific toolchain settings
+  toolchain :gcc
+
+  # include the GEM box
+  conf.gembox 'default'
+
+  conf.cc.defines << 'MRB_USE_FLOAT32'
+
+  # Turn on `enable_debug` for better debugging
+  conf.enable_debug
+  conf.enable_test
+  conf.enable_bintest
+end