Build RP2350-ARM with -O3 (#3124)

* Build RP2350-ARM with -O3

Using -O3 identified a potential issue in #3122, so replace -Os with -O3
for the RP2350 builds in CI

* Turn off fake warnings in LeaMDNS

* More bogus warnings

Author: earlephilhower

libraries/LEAmDNS/src/LEAmDNS_Helpers.cpp

@@ -451,6 +451,13 @@ MDNSResponder::_findService(const MDNSResponder::hMDNSService p_hService) {
     SERVICE TXT
 */
 
+// There are many strncpy()s here that immediately set the terminating \0, but GCC
+// doesn't notice that and emits a warning at -O3 -Wall -Wextra.  After inspection,
+// disable that specific warning since it's not a real problem
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstringop-truncation"
+
 /*
     MDNSResponder::_allocServiceTxt
 */
@@ -489,6 +496,8 @@ MDNSResponder::_allocServiceTxt(MDNSResponder::stcMDNSService* p_pService, const
     return pTxt;
 }
 
+#pragma GCC diagnostic pop
+
 /*
     MDNSResponder::_releaseServiceTxt
 */

libraries/LEAmDNS/src/LEAmDNS_Structs.cpp

@@ -26,6 +26,13 @@
 #include "LEAmDNS_Priv.h"
 #include "LEAmDNS_lwIPdefs.h"
 
+// There are many strncpy()s here that immediately set the terminating \0, but GCC
+// doesn't notice that and emits a warning at -O3 -Wall -Wextra.  After inspection,
+// disable that specific warning since it's not a real problem
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstringop-truncation"
+
 namespace esp8266 {
 
 /*
@@ -2020,3 +2027,5 @@ MDNSResponder::stcMDNSSendParameter::findCachedDomainOffset(const void* p_pHostn
 }  // namespace MDNSImplementation
 
 }  // namespace esp8266
+
+#pragma GCC diagnostic pop

tests/build-rp2350.sh

@@ -15,7 +15,7 @@ elif [ "$BUILD_PARITY" = "odd" ]; then
     rem=1
 fi
 
-export FQBN=pico:rp2040:rpipico2:flash=4194304_0,arch=arm,freq=150,opt=Small,rtti=Disabled,stackprotect=Disabled,exceptions=Disabled,dbgport=Disabled,dbglvl=None,usbstack=picosdk,ipbtstack=ipv4only,uploadmethod=default
+export FQBN=pico:rp2040:rpipico2:flash=4194304_0,arch=arm,freq=150,opt=Optimize3,rtti=Disabled,stackprotect=Disabled,exceptions=Disabled,dbgport=Disabled,dbglvl=None,usbstack=picosdk,ipbtstack=ipv4only,uploadmethod=default
 export PICO_BOARD=rp2350
 
 install_arduino nodebug