(2.4) Backports from master branch (#7854)

* restore Google Test 1.7.0 (get patch)

* ts: update Google Test to 1.8.0 release

https://github.com/google/googletest

* ts: re-apply OpenCV patch for gtest

* ts: fixes for gtest 1.8.0

* ts: workaround MSVS2015 problem in gtest

fix compiler error when building with gnu-5 toolchain (eg as currently shipped with crystax.org android ndk, and presumably soon with android studio).

"ts_perf.cpp ....error: 'errno' was not declared in this scope
      int err=errno;"

--perf_instrument parameter now has int type and 0, 1, 2 modes (1 - simple trees, 2 - expanded trees for functions with same name but different calling address);

Maximum depth limit var was added to the instrumentation structure;

Trace names output console output fix: improper tree formatting could happen;
Output in case of error was added;

Custom regions improvements;

Improved timing and weight calculation for parallel regions; New TC (threads counter) value to indicate how many different threads accessed particular node;

parallel_for, warnings fixes and ReturnAddress code from Alexander Alekhin;

- calculate ticksTotal instead of ticksMean
- local / global width is based on ticksTotal value
- added instrumentation for OpenCL program compilation
- added instrumentation for OpenCL kernel execution

  * check compiler support
  * check HW support before executing
  * add test doing round trip conversion from / to FP32
  * treat array correctly if size is not multiple of 4
  * add declaration to prevent warning
  * make it possible to enable fp16 on 32bit ARM
  * let the conversion possible on non-supported HW, too.
  * add test using both HW and SW implementation

All of these: (performance) Prefer prefix ++/-- operators for non-primitive types.
[modules/calib3d/src/fundam.cpp:1049] -> [modules/calib3d/src/fundam.cpp:1049]: (style) Same expression on both sides of '&&'.

cosmetic changes to fix this warning.
real bugs not found

`has()` only tests for an argument presence which is always true for
arguments with default values. Use `get<bool>()` to check the value
instead.

(cherry picked from commit 47cee871)

Also:
- Silence clang warnings about unsupported command line arguments
- Add diagnostic print to calib3d test
- Fixed perf test relative error check
- Fix iOS build problem

- Previous version just checked option support, but not enable it.
- Also OpenCV tests reports invalid AVX and AVX2 support status.