Get basic profiler working again

BUILD

Makefile

build.yaml

gRPC.podspec

grpc.gyp

src/core/profiling/basic_timers.c

src/core/profiling/timers.h

src/core/support/time_posix.c

src/core/support/time_precise.c

src/core/support/time_precise.h

tools/doxygen/Doxyfile.core.internal

tools/profile_analyzer/profile_analyzer.py

tools/run_tests/sources_and_headers.json

vsprojects/vcxproj/gpr/gpr.vcxproj

vsprojects/vcxproj/gpr/gpr.vcxproj.filters