SwiftDemangle: disable ABI breaking checks

Since this library uses ADT headers, it will pull in a dependency for
LLVMSupport (Error.cpp has the necessary variable declaration for ABI breaking
checks).  Disable the ABI breaking check validation as we only use the library
for header-only dependencies.  Avoiding this dependency shaves nearly 900 KiB
from the resultant binary.

Author: compnerd

lib/Demangling/CMakeLists.txt

@@ -1,13 +1,15 @@
-add_swift_library(swiftDemangling STATIC
-  Demangler.cpp
-  Context.cpp
-  ManglingUtils.cpp
-  NodeDumper.cpp
-  NodePrinter.cpp
-  OldDemangler.cpp
-  OldRemangler.cpp
-  Punycode.cpp
-  Remangler.cpp
-  TypeDecoder.cpp
-  )
+add_swift_library(swiftDemangling
+                  STATIC
+                    Demangler.cpp
+                    Context.cpp
+                    ManglingUtils.cpp
+                    NodeDumper.cpp
+                    NodePrinter.cpp
+                    OldDemangler.cpp
+                    OldRemangler.cpp
+                    Punycode.cpp
+                    Remangler.cpp
+                    TypeDecoder.cpp
+                  C_COMPILE_FLAGS
+                    -DLLVM_DISABLE_ABI_BREAKING_CHECKS_ENFORCING=1)
 

lib/SwiftDemangle/CMakeLists.txt

@@ -1,7 +1,11 @@
-add_swift_library(swiftDemangle SHARED
-  SwiftDemangle.cpp
-  MangleHack.cpp
-  LINK_LIBRARIES swiftDemangling)
+add_swift_library(swiftDemangle
+                  SHARED
+                    SwiftDemangle.cpp
+                    MangleHack.cpp
+                  LINK_LIBRARIES
+                    swiftDemangling
+                  C_COMPILE_FLAGS
+                    -DLLVM_DISABLE_ABI_BREAKING_CHECKS_ENFORCING=1)
 
 swift_install_in_component(compiler
     TARGETS swiftDemangle