Revert "CMake patches for QNX Support (#178)" (#179)

This reverts commit 5d9f739.

The QNX-specific changes have been moved to the relevant repos instead,
as they don't belong in the general cmake rules.

Author: adharsh

.cmake-format.yaml

@@ -54,7 +54,7 @@ lint:
   max_branches: 40 # Default target: 12
   max_arguments: 6 # Default target: 5
   max_localvars: 15
-  max_statements: 130 # Default target: 50
+  max_statements: 125 # Default target: 50
 encode:
   emit_byteorder_mark: false
   input_encoding: utf-8

CompileOptions.cmake

@@ -135,10 +135,6 @@ function(swift_set_compile_options)
     endif()
   endif()
 
-  if(CMAKE_SYSTEM_NAME MATCHES "QNX")
-    list(APPEND all_flags -D_QNX_SOURCE)
-  endif ()
-
   list(APPEND all_flags
        -Wall
        -Wcast-align

TestTargets.cmake

@@ -299,9 +299,6 @@ function(swift_add_test target)
   endif()
   if(x_LINK)
     target_link_libraries(${target} PRIVATE ${x_LINK})
-    if(CMAKE_SYSTEM_NAME MATCHES "QNX")
-      target_link_libraries(${target} PRIVATE regex)
-    endif ()
   endif()
 
   if (NOT ${PROJECT_NAME}_BUILD_TESTS)