fixed incorrect ZAM optimization of expressions seen in single-statement inlined functions

testing/btest/Baseline/opt.regress-inlining-temps/output

@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+T, [field1=3], 3

testing/btest/opt/regress-inlining-temps.zeek

@@ -0,0 +1,30 @@
+# @TEST-DOC: Regression test for incorrect reuse of temporaries when inlining
+# @TEST-REQUIRES: test "${ZEEK_USE_CPP}" != "1"
+# @TEST-EXEC: zeek -b -O ZAM %INPUT >output
+# @TEST-EXEC: btest-diff output
+
+type R: record {
+	field1: count;
+};
+
+global yes = T;
+
+function pred(my_R: R): bool
+	{
+	# In the following, my_R$field1 will never be evaluated ...
+	if ( yes || my_R$field1 == 4 )
+		return T;
+	else
+		return F;
+	}
+
+event zeek_init()
+	{
+	local my_R = R($field1=3);
+
+	# ... prior to the regression, the third argument in this print
+	# was taken from the temporary in pred() that *would* have held
+	# my_R$field1 had that ever been evaluated, but instead it holds
+	# the default ZVal value of 0.
+	print pred(my_R), my_R, my_R$field1;
+	}