[lldb/test] Fix TestScriptedProcess.py failures on arm linux bots

This patch tentatively fixes TestScriptedProcess.py which has been
failing on the `lldb-arm-ubuntu` & `lldb-aarch64-ubuntu` bots:

- https://lab.llvm.org/buildbot/#/builders/17/builds/44965
- https://lab.llvm.org/buildbot/#/builders/96/builds/48152

According to the test log, on those systems, the clang driver that build
the test binary doesn't have the `-m` flag to specify the architure so
this patch replaces it with the `-target` flag using `clang -dumpmachine`
to get the host triple.

Signed-off-by: Med Ismail Bennani <[email protected]>

Author: medismailben

lldb/test/API/functionalities/scripted_process/Makefile

@@ -2,12 +2,14 @@ CXX_SOURCES := main.cpp
 ENABLE_THREADS := YES
 LD_EXTRAS := -L. -lbaz -I.
 
-override ARCH := $(shell uname -m)
+override TRIPLE := $(shell $(CC) -dumpmachine)
+
+CXXFLAGS_EXTRAS := -target $(TRIPLE)
 
 all: libbaz.dylib a.out
 
 libbaz.dylib: baz.cpp
-	$(MAKE) -f $(MAKEFILE_RULES) ARCH=$(ARCH) \
+	$(MAKE) -f $(MAKEFILE_RULES) \
 		DYLIB_ONLY=YES DYLIB_NAME=baz DYLIB_CXX_SOURCES=baz.cpp
 
 include Makefile.rules