PR tree-optimization/79699 - small memory leak in MPFR

gcc/ChangeLog:

	PR tree-optimization/79699
	* context.c (context::~context): Free MPFR caches to avoid
	a memory leak on program exit.

diff --git a/gcc/context.c b/gcc/context.c
index a7ded9c..d2009b9 100644
--- a/gcc/context.c
+++ b/gcc/context.c
@@ -23,6 +23,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "context.h"
 #include "pass_manager.h"
 #include "dumpfile.h"
+#include "mpfr.h"
 
 /* The singleton holder of global state: */
 gcc::context *g;
@@ -42,4 +43,7 @@ gcc::context::~context ()
 {
   delete m_passes;
   delete m_dumps;
+
+  /* Release MPFR caches to avoid Valgrind leak reports.  */
+  mpfr_free_cache ();
 }