Fix compiler lookup when specified without path

r259433 introduced a regression, where if a compiler is specified without a path (e.g., CC=clang,
relying on the fact that clang is in $PATH), then the test suite would fail (at the compiler
version detection step) because realpath would interpret this as a path relative to cwd). The fix
is to perform the $PATH expansion (via `which`) before the realpath step.

llvm-svn: 259484

lldb/packages/Python/lldbsuite/test/lldbtest.py

@@ -1945,11 +1945,10 @@ class Base(unittest2.TestCase):
         """ Returns a string that represents the compiler version.
             Supports: llvm, clang.
         """
-        from .lldbutil import which
         version = 'unknown'
 
         compiler = self.getCompilerBinary()
-        version_output = system([[which(compiler), "-v"]])[1]
+        version_output = system([[compiler, "-v"]])[1]
         for line in version_output.split(os.linesep):
             m = re.search('version ([0-9\.]+)', line)
             if m:

lldb/packages/Python/lldbsuite/test/plugins/builder_base.py

@@ -15,6 +15,7 @@ variable.
 import os, sys
 import platform
 import lldbsuite.test.lldbtest as lldbtest
+import lldbsuite.test.lldbutil as lldbutil
 
 def getArchitecture():
     """Returns the architecture in effect the test suite is running with."""
@@ -23,6 +24,7 @@ def getArchitecture():
 def getCompiler():
     """Returns the compiler in effect the test suite is running with."""
     compiler = os.environ.get("CC", "clang")
+    compiler = lldbutil.which(compiler)
     return os.path.realpath(compiler)
 
 def getArchFlag():