Log Message:
Update to 3.7.1

Changelog:
Major changes in 3.7.1
======================

* 3.7.0 was released with an inadvertent change to the signature of the C
  API function: LLVMBuildLandingPad, which made the C API incompatible with
  prior releases.  This has been corrected in LLVM 3.7.1.

  As a result of this change, 3.7.0 is not ABI compatible with 3.7.1.

  +----------------------------------------------------------------------------+
  | History of the LLVMBuildLandingPad() function                              |
  +===========================+================================================+
  | 3.6.2 and prior releases  | LLVMBuildLandingPad(LLVMBuilderRef,            |
  |                           |                     LLVMTypeRef,               |
  |                           |                     LLVMValueRef,              |
  |                           |                     unsigned, const char*)     |
  +---------------------------+------------------------------------------------+
  | 3.7.0                     | LLVMBuildLandingPad(LLVMBuilderRef,            |
  |                           |                     LLVMTypeRef,               |
  |                           |                     unsigned, const char*)     |
  +---------------------------+------------------------------------------------+
  | 3.7.1 and future releases | LLVMBuildLandingPad(LLVMBuilderRef,            |
  |                           |                     LLVMTypeRef,               |
  |                           |                     LLVMValueRef,              |
  |                           |                     unsigned, const char*)     |
  +---------------------------+------------------------------------------------+