[libFuzzer] [Windows] Include windows.h and psapi.h with lowercase

This fixes building on a case sensitive filesystem with mingw-w64
headers, where all headers are lowercase, and matches how these
headers are included elsewhere in compiler-rt.

Also include these headers with angle brackets, as they are system
headers.

Differential Revision: https://reviews.llvm.org/D51913

llvm-svn: 341983

compiler-rt/lib/fuzzer/FuzzerExtFunctionsDlsymWin.cpp

@@ -13,10 +13,10 @@
 
 #include "FuzzerExtFunctions.h"
 #include "FuzzerIO.h"
-#include "Windows.h"
+#include <windows.h>
 
 // This must be included after Windows.h.
-#include "Psapi.h"
+#include <psapi.h>
 
 namespace fuzzer {
 

compiler-rt/lib/fuzzer/FuzzerUtilWindows.cpp

@@ -24,7 +24,7 @@
 #include <windows.h>
 
 // This must be included after windows.h.
-#include <Psapi.h>
+#include <psapi.h>
 
 namespace fuzzer {