Fix typo + remove duplicate rt_configOption declaration

Author: wilzbach

src/core/internal/parseoptions.d

@@ -14,6 +14,8 @@ import core.stdc.stdio;
 import core.stdc.ctype;
 import core.stdc.string;
 import core.vararg;
+import core.internal.traits : externDFunc;
+
 
 @nogc nothrow:
 extern extern(C) string[] rt_args();
@@ -22,6 +24,10 @@ extern extern(C) __gshared bool rt_envvars_enabled;
 extern extern(C) __gshared bool rt_cmdline_enabled;
 extern extern(C) __gshared string[] rt_options;
 
+alias rt_configCallBack = string delegate(string) @nogc nothrow;
+alias fn_configOption = string function(string opt, scope rt_configCallBack dg, bool reverse) @nogc nothrow;
+alias rt_configOption = externDFunc!("rt.config.rt_configOption", fn_configOption);
+
 /**
 * initialize members of struct CFG from rt_config options
 *
@@ -32,13 +38,6 @@ extern extern(C) __gshared string[] rt_options;
 */
 bool initConfigOptions(CFG)(ref CFG cfg, string cfgname)
 {
-    import core.internal.traits : externDFunc;
-
-    alias rt_configCallBack = string delegate(string) @nogc nothrow;
-    alias fn_configOption = string function(string opt, scope rt_configCallBack dg, bool reverse) @nogc nothrow;
-
-    alias rt_configOption = externDFunc!("rt.config.rt_configOption", fn_configOption);
-
     string parse(string opt) @nogc nothrow
     {
         if (!parseOptions(cfg, opt))

src/core/runtime.d

@@ -655,10 +655,7 @@ extern (C) UnitTestResult runModuleUnitTests()
         }
     }
 
-    import core.internal.traits : externDFunc;
-    alias rt_configCallBack = string delegate(string) @nogc nothrow;
-    alias fn_configOption = string function(string opt, scope rt_configCallBack dg, bool reverse) @nogc nothrow;
-    alias rt_configOption = externDFunc!("rt.config.rt_configOption", fn_configOption);
+    import core.internal.parseoptions : rt_configOption;
 
     if (results.passed != results.executed)
     {

src/rt/config.d

@@ -60,7 +60,7 @@ alias rt_configCallBack = string delegate(string) @nogc nothrow;
 
 /**
 * get a druntime config option using standard configuration options
-*      opt             name of the option to retreive
+*      opt             name of the option to retrieve
 *      dg              if non-null, passes the option through this
 *                      delegate and only returns its return value if non-null
 *      reverse         reverse the default processing order cmdline/envvar/rt_options