Fix typo "fuction" noticed in comments in AssumptionCache.h, and also all the other files that have the same typo. All comments, no functionality change! (Merely a "fuctionality" change.)

Bonus change to remove emacs major mode marker from SystemZMachineFunctionInfo.cpp because emacs already knows it's C++ from the extension. Also fix typo "appeary" in AMDGPUMCAsmInfo.h.

llvm-svn: 243585
diff --git a/llvm/lib/Target/SystemZ/SystemZMachineFunctionInfo.cpp b/llvm/lib/Target/SystemZ/SystemZMachineFunctionInfo.cpp
index 00572d0b..1a7c0d7 100644
--- a/llvm/lib/Target/SystemZ/SystemZMachineFunctionInfo.cpp
+++ b/llvm/lib/Target/SystemZ/SystemZMachineFunctionInfo.cpp
@@ -1,4 +1,4 @@
-//== SystemZMachineFuctionInfo.cpp - SystemZ machine function info-*- C++ -*-=//
+//=== SystemZMachineFunctionInfo.cpp - SystemZ machine function info ------===//
 //
 //                     The LLVM Compiler Infrastructure
 //