HPCC-14741 Fix various warnings in jlib on power8

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>

system/jlib/jdebug.cpp

@@ -311,6 +311,9 @@ static double cycleToMilliScale;
 
 void calibrate_timing()
 {
+    cycleToNanoScale = 1.0;
+    cycleToMicroScale = 1.0;
+    cycleToMilliScale = 1.0;
 #if defined(_ARCH_X86_) || defined(_ARCH_X86_64_)
     if (useRDTSC) {
         unsigned long eax;

system/jlib/jexcept.cpp

@@ -986,6 +986,8 @@ void excsighandler(int signum, siginfo_t *info, void *extra)
     static byte nested=0;
     if (nested++)
         return;
+
+    excsignal = 0;
 #ifdef NO_LINUX_SEH
     signal(SIGSEGV, SIG_DFL);
     signal(SIGBUS, SIG_DFL);

system/jlib/jutil.cpp

@@ -567,7 +567,7 @@ void resetUniqueId()
 //-----------------------------------------------------------------------
 
 #define make_numtostr(VTYPE)                                    \
-    int numtostr(char *dst, VTYPE _value)                    \
+    int numtostr(char *dst, signed VTYPE _value)                    \
 {                                                                \
     int c;                                                        \
     unsigned VTYPE value;                                        \
@@ -2245,7 +2245,7 @@ StringBuffer jlib_decl passwordInput(const char* prompt, StringBuffer& passwd)
     tcsetattr(termfd, TCSAFLUSH, &set_term);
     char c = EOF;
     int rd = ::read(termfd,&c,1);
-    while ((rd==1)&&(c!='\r')&&(c!='\n')&&(c!=EOF)) {
+    while ((rd==1)&&(c!='\r')&&(c!='\n')) {
         passwd.append(c);
         rd = ::read(termfd,&c,1);
     }