[libcxx] Do not include the C math.h header before __config
Summary:
Certain C libraries require configuration macros defined in __config
to provide the correct functionality for libc++. This patch ensures
that the C header math.h is always included after the __config
header. It also adds a Windows-specific #if guard for the case when
the C math.h file is included the second time, as suggested by
Marshall in https://reviews.llvm.org/rL323490.
Fixes PR36382.
Reviewers: mclow.lists, EricWF
Reviewed By: mclow.lists
Subscribers: cfe-commits, pcc, christof, rogfer01
Differential Revision: https://reviews.llvm.org/D43579
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@325760 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed
