[benchmark] Fix win32 link on case-sensitive fs

[jschueller]

Summary

This fixes cross-builds with MinGW from case-sensitive file-systems (on Linux)

[lebedev.ri]

Please can you submit this upstream first?

[RKSimon]

In D61371#1485911, @lebedev.ri wrote:

Please can you submit this upstream first?

https://github.com/google/benchmark/blob/master/src/CMakeLists.txt

Yes, please create a pull request on google-benchmark's github first

[jschueller]

ok, see https://github.com/google/benchmark/pull/812

[lebedev.ri]

1. Please note there is one more copy of benchmark, in testsuite repo. Not sure if you care about that one, but it may be better to fix this in all of them at once.
2. There is a llvm/utils/benchmark/README.LLVM and libcxx/utils/google-benchmark/README.LLVM (and in testsuite, if you change that one too) that needs to be updated to document this cherry-pick from upstream.

[RKSimon]

In D61371#1487338, @jschueller wrote:

ok, see https://github.com/google/benchmark/pull/812

Any progress?

[lebedev.ri]

In D61371#1559587, @RKSimon wrote:

In D61371#1487338, @jschueller wrote:

ok, see https://github.com/google/benchmark/pull/812

Any progress?

@jschueller never replied there, so it got stuck.
I could take that over, but i'd need an *explicit* acknowledgement that it is ok to steal that from @jschueller from @jschueller.

[jschueller]

ok, you can "steal" my patch : )

[lebedev.ri]

Submitted
https://github.com/google/benchmark/pull/840
yesterday, it just landed.
Please update README.llvm in these bundled copies to reflect this cherry-pick.
(BTW, there is one more copy, in test-suite, not sure if that matters)

[RKSimon]

@lebedev.ri I think you can commandeer this

libcxx/trunk/utils/google-benchmark/README.LLVM

 LLVM notes
 ----------
 
 This directory contains the Google Benchmark source code with some unnecessary
 files removed. Note that this directory is under a different license than
 libc++.
 
 Changes:
 * https://github.com/google/benchmark/commit/4abdfbb802d1b514703223f5f852ce4a507d32d2
   is applied on top of
   https://github.com/google/benchmark/commit/4528c76b718acc9b57956f63069c699ae21edcab
   to add RISC-V timer support.
+* https://github.com/google/benchmark/commit/8e48105d465c586068dd8e248fe75a8971c6ba3a
+  is applied on top of
+  https://github.com/google/benchmark/commit/4528c76b718acc9b57956f63069c699ae21edcab
+  to fix cross-build from linux to windows via MinGW.

libcxx/trunk/utils/google-benchmark/src/CMakeLists.txt

 target_link_libraries(benchmark  ${BENCHMARK_CXX_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
 find_library(LIBRT rt)
 if(LIBRT)
   target_link_libraries(benchmark ${LIBRT})
 endif()
 
 # We need extra libraries on Windows
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  target_link_libraries(benchmark Shlwapi)
+  target_link_libraries(benchmark shlwapi)
 endif()
 
 # We need extra libraries on Solaris
 if(${CMAKE_SYSTEM_NAME} MATCHES "SunOS")
   target_link_libraries(benchmark kstat)
 endif()
 
 # Benchmark main library

llvm/trunk/utils/benchmark/README.LLVM

 * https://github.com/google/benchmark/commit/439d6b1c2a6da5cb6adc4c4dfc555af235722396
   is applied to fix building with MinGW headers for ARM
 * https://github.com/google/benchmark/commit/a9b31c51b1ee7ec7b31438c647123c2cbac5d956
   is applied to disable exceptions in Microsoft STL when exceptions are disabled
 * Disabled CMake get_git_version as it is meaningless for this in-tree build,
   and hardcoded a null version
 * https://github.com/google/benchmark/commit/4abdfbb802d1b514703223f5f852ce4a507d32d2
   is applied on top of v1.4.1 to add RISC-V timer support.
+* https://github.com/google/benchmark/commit/8e48105d465c586068dd8e248fe75a8971c6ba3a
+  is applied on top of v1.4.1 to fix cross-build from linux to windows via MinGW.

llvm/trunk/utils/benchmark/src/CMakeLists.txt

 target_link_libraries(benchmark  ${BENCHMARK_CXX_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
 find_library(LIBRT rt)
 if(LIBRT)
   target_link_libraries(benchmark ${LIBRT})
 endif()
 
 # We need extra libraries on Windows
 if(${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  target_link_libraries(benchmark Shlwapi)
+  target_link_libraries(benchmark shlwapi)
 endif()
 
 # We need extra libraries on Solaris
 if(${CMAKE_SYSTEM_NAME} MATCHES "SunOS")
   target_link_libraries(benchmark kstat)
 endif()
 
 # Benchmark main library