[BUG] QNX compilation failure on v1.8.3. Patch suggestion.

[Arech]

Describe the bug There are some trivial compilation errors due -Werror and old-style C-casts in QNX specific block of src/sysinfo.cc

FAILED: src/CMakeFiles/benchmark.dir/sysinfo.cc.o
qnx-sdp/qnx710/host/linux/x86_64/usr/bin/ntoaarch64-g++ --sysroot=qnx-sdp/qnx710/target/qnx7 -DBENCHMARK_STATIC_DEFINE -DHAVE_STD_REGEX -DHAVE_STEADY_CLOCK -D_QNX_SOURCE -I/home/user/vcpkg/buildtrees/benchmark/src/v1.8.3-eb6e61b079.clean/include -I/home/user/vcpkg/buildtrees/benchmark/src/v1.8.3-eb6e61b079.clean/src -fexceptions -D_XOPEN_SOURCE=600 -D_POSIX_C_SOURCE=200112L -D_QNX_SOURCE -fexceptions -D_XOPEN_SOURCE=600 -D_POSIX_C_SOURCE=200112L -D_QNX_SOURCE  -Wall  -Wextra  -Wshadow  -Wfloat-equal  -Wold-style-cast  -Werror  -Wsuggest-override  -pedantic  -pedantic-errors  -fstrict-aliasing  -Wno-deprecated-declarations  -Wno-deprecated  -Wstrict-aliasing -g -std=c++11 -fvisibility=hidden -fvisibility-inlines-hidden -MD -MT src/CMakeFiles/benchmark.dir/sysinfo.cc.o -MF src/CMakeFiles/benchmark.dir/sysinfo.cc.o.d -o src/CMakeFiles/benchmark.dir/sysinfo.cc.o -c /home/user/vcpkg/buildtrees/benchmark/src/v1.8.3-eb6e61b079.clean/src/sysinfo.cc
/home/user/vcpkg/buildtrees/benchmark/src/v1.8.3-eb6e61b079.clean/src/sysinfo.cc: In function 'double benchmark::{anonymous}::GetCPUCyclesPerSecond(benchmark::CPUInfo::Scaling)':
/home/user/vcpkg/buildtrees/benchmark/src/v1.8.3-eb6e61b079.clean/src/sysinfo.cc:774:69: error: use of old-style cast to 'int64_t' {aka 'long int'} [-Werror=old-style-cast]
   return static_cast<double>((int64_t)(SYSPAGE_ENTRY(cpuinfo)->speed) *
                                                                     ^
                              ---------
                              static_cast<int64_t> (                  )
/home/user/vcpkg/buildtrees/benchmark/src/v1.8.3-eb6e61b079.clean/src/sysinfo.cc:775:51: error: use of old-style cast to 'int64_t' {aka 'long int'} [-Werror=old-style-cast]
                              (int64_t)(1000 * 1000));
                                                   ^
                              ---------
                              static_cast<int64_t> ()
cc1plus: all warnings being treated as errors

Patch suggestion

diff --git a/src/sysinfo.cc b/src/sysinfo.cc
index 922e83a..ec9fd35 100644
--- a/src/sysinfo.cc
+++ b/src/sysinfo.cc
@@ -771,8 +771,8 @@ double GetCPUCyclesPerSecond(CPUInfo::Scaling scaling) {
   kstat_close(kc);
   return clock_hz;
 #elif defined(BENCHMARK_OS_QNX)
-  return static_cast<double>((int64_t)(SYSPAGE_ENTRY(cpuinfo)->speed) *
-                             (int64_t)(1000 * 1000));
+  return static_cast<double>(static_cast<int64_t>(SYSPAGE_ENTRY(cpuinfo)->speed) *
+                             static_cast<int64_t>(1000 * 1000));
 #elif defined(BENCHMARK_OS_QURT)
   // QuRT doesn't provide any API to query Hexagon frequency.
   return 1000000000;

[LebedevRI]

@Arech do you feel like submitting it as a pull request? :)

[Arech]

@LebedevRI will do within about week, ok? Need to finish with some important work stuff first.