[llvm] Fix file ignoring inside directories

We have some ! patterns in the .gitignore (for the projects and runtimes
directories), and those patterns end up overriding the previous file
ignores, such that e.g. a .swp file inside the runtimes directory isn't
ignored. Move the file ignores last to ensure they take effect.

Differential Revision: https://reviews.llvm.org/D73253

llvm/.gitignore

@@ -7,21 +7,8 @@
 #==============================================================================#
 
 #==============================================================================#
-# File extensions to be ignored anywhere in the tree.
+# Nested build directory.
 #==============================================================================#
-# Temp files created by most text editors.
-*~
-# Merge files created by git.
-*.orig
-# Byte compiled python modules.
-*.pyc
-# vim swap files
-.*.sw?
-.sw?
-#OS X specific files.
-.DS_store
-
-# Nested build directory
 /build
 
 #==============================================================================#
@@ -82,3 +69,19 @@ docs/_build
 #==============================================================================#
 bindings/go/llvm/llvm_config.go
 bindings/go/llvm/workdir
+
+#==============================================================================#
+# File extensions to be ignored anywhere in the tree.
+# Placed at the end to override any previous ! patterns.
+#==============================================================================#
+# Temp files created by most text editors.
+*~
+# Merge files created by git.
+*.orig
+# Byte compiled python modules.
+*.pyc
+# vim swap files
+.*.sw?
+.sw?
+#OS X specific files.
+.DS_store