[SETTINGS] Cleanup the settings generator a bit

- Don't include target.h explicitely, it's already included
by platform.h
- Fix an error in compiled file as a test for discovering
contstants. Since we rely on compiler errors to give us the
resolved value, that lets us get one extra value on each run
- Always compile the test files for setting discovery in c++11
even if no -std=XXX argument is passed from the caller.

src/utils/compiler.rb

@@ -57,6 +57,7 @@ class Compiler
     def default_args
         cflags = Shellwords.split(ENV["CFLAGS"] || "")
         args = [@path]
+        args << "-std=c++11"
         cflags.each do |flag|
             # Don't generate temporary files
             if flag == "" || flag == "-MMD" || flag == "-MP" || flag.start_with?("-save-temps")
@@ -67,7 +68,7 @@ class Compiler
                 next
             end
             if flag.start_with? "-std="
-                flag = "-std=c++11"
+                next
             end
             if flag.start_with? "-D'"
                 # Cleanup flag. Done by the shell when called from

src/utils/settings.rb

@@ -718,7 +718,7 @@ class Generator
     def compile_test_file(prog)
         buf = StringIO.new
         # cstddef for offsetof()
-        headers = ["platform.h", "target.h", "cstddef"]
+        headers = ["platform.h", "cstddef"]
         @data["groups"].each do |group|
             gh = group["headers"]
             if gh
@@ -925,7 +925,7 @@ class Generator
             buf << "static_assert(V == 42 && 0 == 1, \"FAIL\");\n"
             buf << "public:\n"
             buf << "Fail() {};\n"
-            buf << "int64_t v = V\n"
+            buf << "int64_t v = V;\n"
             buf << "};\n"
             ii  = 0
             s.each do |c|