Robustify toolchain string matching

cmake/common/px4_base.cmake

@@ -512,7 +512,7 @@ function(px4_add_common_flags)
 		list(APPEND warnings -Wframe-larger-than=1024)
 	endif()
 
-	if (${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
+	if (${CMAKE_C_COMPILER_ID} MATCHES ".*Clang.*")
 		# QuRT 6.4.X compiler identifies as Clang but does not support this option
 		if (NOT ${OS} STREQUAL "qurt")
 			list(APPEND warnings
@@ -540,7 +540,7 @@ function(px4_add_common_flags)
 		-fdata-sections
 		)
 
-	if (NOT ${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
+	if (NOT ${CMAKE_C_COMPILER_ID} MATCHES ".*Clang.*")
 		list(APPEND optimization_flags
 			-fno-strength-reduce
 			-fno-builtin-printf
@@ -554,7 +554,7 @@ function(px4_add_common_flags)
 		-Wnested-externs
 		)
 
-	if (NOT ${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
+	if (NOT ${CMAKE_C_COMPILER_ID} MATCHES ".*Clang.*")
 		list(APPEND c_warnings
 			-Wold-style-declaration
 			-Wmissing-parameter-type
@@ -633,16 +633,10 @@ function(px4_add_common_flags)
 		-DCONFIG_ARCH_BOARD_${board_config}
 		)
 
-	if (NOT ${CMAKE_C_COMPILER_ID} STREQUAL "Clang")
-		set(added_exe_link_flags
-			-Wl,--warn-common
-			-Wl,--gc-sections
-			)
-	else()
+
 		set(added_exe_link_flags
 			-Wl,--warn-common
 			)
-	endif()
 
 	# output
 	foreach(var ${inout_vars})

cmake/toolchains/Toolchain-posix-clang-native.cmake

-
-set(WARNINGS
-    -Wall
-    -Werror
-    -Wextra
-    -Wdouble-promotion
-    -Wshadow
-    -Wfloat-equal
-    -Wframe-larger-than=1024
-    -Wpointer-arith
-    -Wlogical-op
-    -Wmissing-declarations
-    -Wno-unused-parameter
-    -Werror=format-security
-    -Werror=array-bounds
-    -Wfatal-errors
-    -Wformat=1
-    -Werror=unused-but-set-variable
-    -Werror=unused-variable
-    -Werror=double-promotion
-    -Werror=reorder
-    -Werror=uninitialized
-    -Werror=init-self
-    -Werror=return-type
-    -Werror=deprecated
-    -Werror=unused-private-field
-    -Wno-packed
-    -Wno-frame-larger-than=
-    -Wno-varargs
-    #-Wcast-qual  - generates spurious noreturn attribute warnings,
-    #               try again later
-    #-Wconversion - would be nice, but too many "risky-but-safe"
-    #               conversions in the code
-    #-Wcast-align - would help catch bad casts in some cases,
-    #               but generates too many false positives
-    )
-
-set(OPT_FLAGS
-	-Os -g3
-	)
-
-#=============================================================================
-#		c flags
-#
-set(C_WARNINGS
-	-Wbad-function-cast
-	-Wstrict-prototypes
-	-Wold-style-declaration
-	-Wmissing-parameter-type
-	-Wmissing-prototypes
-	-Wnested-externs
-	)
-set(C_FLAGS
-	-std=gnu99
-	-fno-common
-	-fsanitize=address
-	-fno-omit-frame-pointer
-	)
-
-#=============================================================================
-#		cxx flags
-#
-set(CXX_WARNINGS
-	-Wno-missing-field-initializers
-	-Wno-varargs
-	)
-set(CXX_FLAGS
-	-fno-exceptions
-	-fno-rtti
-	-std=gnu++0x
-	-fno-threadsafe-statics
-	-fsanitize=address
-	-fno-omit-frame-pointer
-	-DCONFIG_WCHAR_BUILTIN
-	-D__CUSTOM_FILE_IO__
-	)
-
-#=============================================================================
-#		ld flags
-#
-set(LD_FLAGS
-	-fsanitize=address
-	-Wl,--warn-common
-	-Wl,--gc-sections
-	)
-
-#=============================================================================
-#		misc flags
-#
-set(VISIBILITY_FLAGS
-	-fvisibility=hidden
-	"-include ${CMAKE_SOURCE_DIR}/src/include/visibility.h"
-	)
-set(EXE_LINK_FLAGS)
-