[gardening] Fix style inconsistencies.

Some places in this header were following the LLVM convention of:

namespace ... {

struct Foo {

};

}

and one-two places had extra indentation. I standardized the code on the LLVM
convention.

Author: gottesmm

stdlib/public/runtime/ImageInspection.h

@@ -25,13 +25,14 @@
 #include <cstdint>
 
 namespace swift {
-  // This is a platform independent version of Dl_info from dlfcn.h
-  struct SymbolInfo {
-    const char *fileName;
-    void *baseAddress;
-    const char *symbolName;
-    void *symbolAddress;
-  };
+
+/// This is a platform independent version of Dl_info from dlfcn.h
+struct SymbolInfo {
+  const char *fileName;
+  void *baseAddress;
+  const char *symbolName;
+  void *symbolAddress;
+};
 
 /// Load the metadata from the image necessary to find a type's
 /// protocol conformance.
@@ -48,6 +49,7 @@ void addImageTypeMetadataRecordBlockCallback(const void *start,
                                              uintptr_t size);
 
 int lookupSymbol(const void *address, SymbolInfo *info);
+
 } // end namespace swift
 
-#endif // SWIFT_RUNTIME_IMAGE_INSPECTION_H
+#endif