ARMC6: To get the right stack trace, use -O0

Verified that `-O1` does not make stack trace while `-O0` does.

Author: andrewc-arm

tools/profiles/debug.json

@@ -16,7 +16,7 @@
                "-Wl,-n"]
     },
     "ARMC6": {
-        "common": ["-c", "--target=arm-arm-none-eabi", "-mthumb", "-g", "-O1",
+        "common": ["-c", "--target=arm-arm-none-eabi", "-mthumb", "-g", "-O0",
                    "-Wno-armcc-pragma-push-pop", "-Wno-armcc-pragma-anon-unions",
                    "-Wno-reserved-user-defined-literal", "-Wno-deprecated-register",
                    "-DMULADDC_CANNOT_USE_R7", "-fdata-sections",