Make MSAN-in-JIT flag optional for CMake builds

The Skia GPU MSAN bot runs >9 hours with this option set and
had to be disabled. We'd like to get test MSAN coverage for the
rest of Skia GPU and turn the bot back on, but need this option.

Change-Id: I1536912e9cfe35c294e750fcd4a1f515209989bc
Bug: b/155148722
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/52908
Presubmit-Ready: Adlai Holler <adlai@google.com>
Tested-by: Adlai Holler <adlai@google.com>
Commit-Queue: Adlai Holler <adlai@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 00cf78b..5e109a6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -168,6 +168,8 @@
 option_if_not_defined(REACTOR_EMIT_ASM_FILE "Emit asm files for JIT functions" FALSE)
 option_if_not_defined(REACTOR_ENABLE_PRINT "Enable RR_PRINT macros" FALSE)
 option_if_not_defined(REACTOR_VERIFY_LLVM_IR "Check reactor-generated LLVM IR is valid even in release builds" FALSE)
+# TODO(b/155148722): Remove when unconditionally instrumenting for all build systems.
+option_if_not_defined(REACTOR_ENABLE_MEMORY_SANITIZER_INSTRUMENTATION "Include JIT in MSAN instrumentation (LLVM backend)" TRUE)
 option_if_not_defined(SWIFTSHADER_LESS_DEBUG_INFO "Generate less debug info to reduce file size" FALSE)
 option_if_not_defined(SWIFTSHADER_ENABLE_VULKAN_DEBUGGER "Enable Vulkan debugger support" FALSE)
 option_if_not_defined(SWIFTSHADER_ENABLE_ASTC "Enable ASTC compressed textures support" TRUE)  # TODO(b/150130101)
@@ -193,10 +195,6 @@
 set(REACTOR_DEFAULT_OPT_LEVEL "" CACHE STRING "Reactor default optimization level")
 set_property(CACHE REACTOR_DEFAULT_OPT_LEVEL PROPERTY STRINGS "None" "Less" "Default" "Aggressive")
 
-# Enable instrumentation of Reactor routines for MemorySanitizer builds (LLVM backend).
-# TODO(b/155148722): Remove when unconditionally instrumenting for all build systems.
-set(REACTOR_ENABLE_MEMORY_SANITIZER_INSTRUMENTATION TRUE)
-
 if(NOT DEFINED SWIFTSHADER_LOGGING_LEVEL)
     set(SWIFTSHADER_LOGGING_LEVEL "Info" CACHE STRING "SwiftShader logging level")
     set_property(CACHE SWIFTSHADER_LOGGING_LEVEL PROPERTY STRINGS "Verbose" "Debug" "Info" "Warn" "Error" "Fatal" "Disabled")