Revert "libcom: properly declare isnan() in C++ code"

This reverts commit 2e89a60c2d.

src/libCom/cppStd/epicsAlgorithm.h

@@ -13,9 +13,7 @@
 #ifndef __EPICS_ALGORITHM_H__
 #define __EPICS_ALGORITHM_H__
 
-#include <cmath>
-
-using std::isnan;
+#include "epicsMath.h"
 
 // The C++ standard only requires types to be less-than comparable, so
 // the epicsMin and epicsMax templates only use operator <

src/libCom/iocsh/iocsh.cpp

@@ -16,7 +16,6 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <errno.h>
-#include <cmath>
 
 #define epicsExportSharedSymbols
 #include "errlog.h"
@@ -32,8 +31,6 @@
 #include "cantProceed.h"
 #include "iocsh.h"
 
-using std::isinf;
-
 extern "C" {
 
 /*

src/libCom/test/epicsAlgorithmTest.cpp

@@ -9,15 +9,11 @@
 // epicsAlgorithmTest.cpp
 //	Authors: Jeff Hill & Andrew Johnson
 
-#include <cmath>
-
 #include "epicsUnitTest.h"
 #include "epicsAlgorithm.h"
 #include "epicsMath.h"
 #include "testMain.h"
 
-using std::isnan;
-
 MAIN(epicsAlgorithm)
 {
     testPlan(22);

src/libCom/test/epicsCalcTest.cpp

@@ -8,7 +8,6 @@
 
 #include <stdlib.h>
 #include <string.h>
-#include <cmath>
 
 #include "epicsUnitTest.h"
 #include "epicsTypes.h"
@@ -17,9 +16,6 @@
 #include "postfix.h"
 #include "testMain.h"
 
-using std::isnan;
-using std::isinf;
-
 /* Infrastructure for running tests */
 
 double doCalc(const char *expr) {