[lmi] Stifling "unused" warnings

[Greg Chicares]

I can't remember why I wrote both these function templates:
  stifle_warning_for_unused_variable()
  stifle_warning_for_unused_value()
when it seems that either should suffice. I've searched the
mailing list and the commit history, but found no rationale.

The patch below [0] swaps the implementations. Rerunning
'nychthemeral_test.sh' with that patch finds no problem.

Therefore, I think we can and should merge these together.
Of the two, I prefer the one whose implementation is "{}",
which is identical to the proposal here:
  https://herbsutter.com/2009/10/18/mailbag-shutting-up-compiler-warnings/
except that Herb would omit "inline" as being unnecessary,
while I would retain it as being harmless and suggestive.

Comments?

---------

[0] "The patch below":

diff --git a/miscellany.hpp b/miscellany.hpp
index 5fd12eaf6..95a9bf8a3 100644
--- a/miscellany.hpp
+++ b/miscellany.hpp
@@ -296,8 +296,10 @@ inline unsigned char lmi_toupper(unsigned char c)
 /// conditional-inclusion [16.1] block.
 
 template<typename T>
-inline void stifle_warning_for_unused_variable(T const&)
-{}
+inline void stifle_warning_for_unused_variable(T const& t)
+{
+    (void)&t;
+}
 
 /// DWISOTT
 ///
@@ -309,9 +311,7 @@ inline void stifle_warning_for_unused_variable(T const&)
 /// for volatile types.
 
 template<typename T>
-inline void stifle_warning_for_unused_value(T const& t)
-{
-    (void)&t;
-}
+inline void stifle_warning_for_unused_value(T const&)
+{}
 
 #endif // miscellany_hpp