CMake: Port the 'ccache' feature

This maps to the CMake variable QT_USE_CCACHE.

Change-Id: I3258027301284d907f6ecde6c65d2c0dde8f0a11
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

configure.cmake

@@ -781,6 +781,12 @@ qt_feature("compile_examples"
     AUTODETECT NOT WASM
 )
 qt_feature_config("compile_examples" QMAKE_PRIVATE_CONFIG)
+qt_feature("ccache"
+    LABEL "Using ccache"
+    AUTODETECT 1
+    CONDITION QT_USE_CCACHE
+)
+qt_feature_config("ccache" QMAKE_PRIVATE_CONFIG)
 qt_feature("dlopen" PRIVATE
     LABEL "dlopen()"
     CONDITION UNIX

util/cmake/configurejson2cmake.py

@@ -819,7 +819,10 @@ def get_feature_mapping():
         "alloc_malloc_h": None,
         "alloc_stdlib_h": None,
         "build_all": None,
-        "ccache": None,
+        "ccache": {
+            "autoDetect": "1",
+            "condition": "QT_USE_CCACHE"
+        },
         "compiler-flags": None,
         "cross_compile": {"condition": "CMAKE_CROSSCOMPILING"},
         "debug_and_release": {