base: Stop both conditionally and unconditionally including cmath.

base/stats/text.cc was both conditionally (in two places) and unconditionally
including cmath. Once should be enough.

Change-Id: I941dfb8631eb71d1a8b423011022f78d628baa33
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/45365
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>

src/base/stats/text.cc

@@ -42,19 +42,9 @@
 #define _GLIBCPP_USE_C99 1
 #endif
 
-#if defined(__sun)
-#include <cmath>
-
-#endif
-
-#include <cassert>
-
-#ifdef __SUNPRO_CC
-#include <cmath>
-
-#endif
 #include "base/stats/text.hh"
 
+#include <cassert>
 #include <cmath>
 #include <fstream>
 #include <iostream>