Revert "Temporarily disable warnings-as-errors"

This reverts commit 782a980283b474880c075656d3eaefb8ce16c028.

Change-Id: I95f145db0a7e5351407402861d68bcb17289c698
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33818
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index bf8a56b..87668b7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -93,14 +93,12 @@
 option(ASAN "Build with address sanitizer" 0)
 option(TSAN "Build with thread sanitizer" 0)
 option(UBSAN "Build with undefined behavior sanitizer" 0)
-option(WARNINGS_AS_ERRORS "Treat all warnings as errors" 0)
+option(WARNINGS_AS_ERRORS "Treat all warnings as errors" 1)
 option(DCHECK_ALWAYS_ON "Check validation macros even in release builds" 0)
 option(REACTOR_EMIT_DEBUG_INFO "Emit debug info for JIT functions" 0)
 option(REACTOR_EMIT_PRINT_LOCATION "Emit printing of location info for JIT functions" 0)
 option(REACTOR_VERIFY_LLVM_IR "Check reactor-generated LLVM IR is valid even in release builds" 0)
 
-set(SPIRV_WERROR OFF CACHE BOOL "TEMPORARY WHILE UPDATING SPIRV-Headers SPIRV-Tools")
-
 if(ARCH STREQUAL "arm")
     set(DEFAULT_REACTOR_BACKEND "Subzero")
 else()