Fix stringification of macro value

level of indirection because STRINGIFY(X) produces "X" regardless of
what value X is defined to be.

Bug: b/174801963
Change-Id: I1b2c1c987417ee1a97e109b52f41bdc865db8c77
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/50908
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>

src/Reactor/ExecutableMemory.cpp

diff --git a/src/Reactor/ExecutableMemory.cpp b/src/Reactor/ExecutableMemory.cpp
index a66bc6d..504dceb 100644
--- a/src/Reactor/ExecutableMemory.cpp
+++ b/src/Reactor/ExecutableMemory.cpp
@@ -42,6 +42,9 @@
 #	define __x86__
 #endif
 
+#define STRINGIFY(x) #x
+#define MACRO_STRINGIFY(x) STRINGIFY(x)
+
 namespace rr {
 namespace {
 
@@ -159,7 +162,7 @@
 // MAP_PRIVATE so that underlying pages aren't shared.
 int anonymousFd()
 {
-	static int fd = memfd_create(#REACTOR_ANONYMOUS_MMAP_NAME, 0);
+	static int fd = memfd_create(MACRO_STRINGIFY(REACTOR_ANONYMOUS_MMAP_NAME), 0);
 	return fd;
 }