[bootstrap] Force SQLite to be picked from the SDK for llbuild

New cmake is looking for sqlite in the wrong place for some reason. We
can fix it by explicitly passing -DSQLite3_INCLUDE_DIR=$(xcrun -sdk
macosx -show-sdk-path)/usr/include in the cmake invocation.

<rdar://problem/57437541>

Author: aciidgh

Utilities/bootstrap

@@ -917,7 +917,18 @@ def build_llbuild(args):
     cmake_cache_path = os.path.join(llbuild_build_dir, "CMakeCache.txt")
     if not os.path.isfile(cmake_cache_path) or not args.swiftc_path in open(cmake_cache_path).read():
         mkdir_p(llbuild_build_dir)
-        cmd = ["cmake", "-G", "Ninja", "-DCMAKE_BUILD_TYPE:=Debug", "-DCMAKE_C_COMPILER:=clang", "-DCMAKE_CXX_COMPILER:=clang++", "-DLLBUILD_SUPPORT_BINDINGS:=Swift", "-DCMAKE_Swift_FLAGS=-sdk %s" % (g_default_sysroot) , "-DSWIFTC_EXECUTABLE:=%s" % (args.swiftc_path), llbuild_source_dir]
+        cmd = [
+            "cmake",
+            "-G", "Ninja",
+            "-DCMAKE_BUILD_TYPE:=Debug",
+            "-DCMAKE_C_COMPILER:=clang",
+            "-DCMAKE_CXX_COMPILER:=clang++",
+            "-DLLBUILD_SUPPORT_BINDINGS:=Swift",
+            "-DCMAKE_Swift_FLAGS=-sdk %s" % (g_default_sysroot),
+            "-DCMAKE_Swift_COMPILER:=%s" % (args.swiftc_path),
+            "-DSQLite3_INCLUDE_DIR=%s/usr/include" % (g_default_sysroot),
+            llbuild_source_dir
+        ]
         subprocess.check_call(cmd, cwd=llbuild_build_dir)
 
     # Build.