Merge pull request #79071 from al45tair/eng/PR-143869185

[Backtracing] Bump minimum deployment targets.

Author: al45tair

stdlib/public/RuntimeModule/CMakeLists.txt

@@ -87,6 +87,16 @@ set(LLVM_OPTIONAL_SOURCES
   get-cpu-context.asm
 )
 
+# We have to build with a deployment target of at least 10.15, otherwise
+# the tests will all fail because dyld will get confused at the use of
+# @rpath (from magic-symbols-for-install-name.c) and the `some Sequence<Frame>`
+# in Backtrace won't be accessible.
+if(SWIFT_DARWIN_DEPLOYMENT_VERSION_OSX VERSION_LESS "10.15")
+  set(osx_deployment_target "10.15")
+else()
+  set(osx_deployment_target "${SWIFT_DARWIN_DEPLOYMENT_VERSION_OSX}")
+endif()
+
 add_swift_target_library(swiftRuntime ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES} IS_STDLIB
   ${RUNTIME_SOURCES}
 
@@ -103,6 +113,8 @@ add_swift_target_library(swiftRuntime ${SWIFT_STDLIB_LIBRARY_BUILD_TYPES} IS_STD
 
   PRIVATE_LINK_LIBRARIES ${swift_runtime_link_libraries}
 
+  DEPLOYMENT_VERSION_OSX ${osx_deployment_target}
+
   SWIFT_COMPILE_FLAGS
     ${SWIFT_STANDARD_LIBRARY_SWIFT_FLAGS}
     ${RUNTIME_COMPILE_FLAGS}

stdlib/public/libexec/swift-backtrace/CMakeLists.txt

@@ -39,11 +39,12 @@ set(BACKTRACING_SOURCES
   Utils.swift
   )
 
-# We have to build with a deployment target of at least 10.14.4, otherwise
+# We have to build with a deployment target of at least 10.15, otherwise
 # the tests will all fail because dyld will get confused at the use of
-# @rpath (from magic-symbols-for-install-name.c).
-if(SWIFT_DARWIN_DEPLOYMENT_VERSION_OSX VERSION_LESS "10.14.4")
-  set(osx_deployment_target "10.14.4")
+# @rpath (from magic-symbols-for-install-name.c) and the `some Sequence<Frame>`
+# in Backtrace won't be accessible.
+if(SWIFT_DARWIN_DEPLOYMENT_VERSION_OSX VERSION_LESS "10.15")
+  set(osx_deployment_target "10.15")
 else()
   set(osx_deployment_target "${SWIFT_DARWIN_DEPLOYMENT_VERSION_OSX}")
 endif()