build-llvm: Update to a recent git master version of llvm

Notable changes since the previous version are:
- Added a lld option for requesting delay loading libraries
- Allowing using custom .edata from input object files in lld (for Wine)
- Fixed llvm-dlltool with symbol renaming with stdcall decorations
- Supporting merging resources from more than one resource object file in lld
- Improved error messages for duplicate or undefined symbols in lld
  (including demangling C++ symbols and printing source locations
  where possible)
- Made lld look for for more library name patterns, matching GNU ld
- Brushed up support for using LLDB for, and building on, mingw
- Implemented initial support for armv7 and aarch64 windows in LLDB

build-llvm.sh

@@ -2,7 +2,7 @@
 
 set -e
 
-: ${LLVM_VERSION:=llvmorg-9.0.0}
+: ${LLVM_VERSION:=c49194969430f0ee817498a7000a979a7a0ded03}
 ASSERTS=OFF
 BUILDDIR=build
 unset HOST